{"id":2615,"date":"2026-07-22T11:43:39","date_gmt":"2026-07-22T04:43:39","guid":{"rendered":"https:\/\/blog.datacore.vn\/?p=2615"},"modified":"2026-07-22T11:43:43","modified_gmt":"2026-07-22T04:43:43","slug":"event-study-chung-khoan-viet-nam","status":"publish","type":"post","link":"https:\/\/blog.datacore.vn\/vi\/event-study-chung-khoan-viet-nam\/","title":{"rendered":"Event Study 2026: X\u00e2y d\u1ef1ng nghi\u00ean c\u1ee9u s\u1ef1 ki\u1ec7n cho ch\u1ee9ng kho\u00e1n Vi\u1ec7t Nam"},"content":{"rendered":"<div class=\"wp-block-group tldr-box is-layout-flow wp-block-group-is-layout-flow\">\n\n\n<p class=\"wp-block-paragraph\"><strong>TL;DR:<\/strong> Event Study l\u00e0 ph\u01b0\u01a1ng ph\u00e1p \u0111\u1ecbnh l\u01b0\u1ee3ng \u0111o l\u01b0\u1eddng vi\u1ec7c m\u1ed9t s\u1ef1 ki\u1ec7n c\u1ee5 th\u1ec3, ch\u1eb3ng h\u1ea1n c\u00f4ng b\u1ed1 c\u1ed5 t\u1ee9c hay \u0111\u01b0\u1ee3c th\u00eam v\u00e0o r\u1ed5 ch\u1ec9 s\u1ed1, c\u00f3 t\u1ea1o ra l\u1ee3i su\u1ea5t b\u1ea5t th\u01b0\u1eddng cho c\u1ed5 phi\u1ebfu hay kh\u00f4ng. B\u00e0i \u0111\u1ea7u ti\u00ean trong series nghi\u00ean c\u1ee9u c\u1ee7a DataCore gi\u1ea3i th\u00edch v\u00ec sao m\u1ed9t Event Study \u0111\u00e1ng tin c\u1eady cho th\u1ecb tr\u01b0\u1eddng ch\u1ee9ng kho\u00e1n Vi\u1ec7t Nam ph\u1ea3i b\u1eaft \u0111\u1ea7u t\u1eeb d\u1eef li\u1ec7u gi\u00e1 l\u1ecbch s\u1eed s\u1ea1ch, ch\u1ee9 kh\u00f4ng ph\u1ea3i t\u1eeb m\u00f4 h\u00ecnh.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">B\u00e0i vi\u1ebft \u0111i qua c\u00e1i b\u1eaby \u00e2m 16,7% do c\u1ed5 t\u1ee9c b\u1eb1ng c\u1ed5 phi\u1ebfu, l\u1ef1a ch\u1ecdn gi\u1eefa gi\u00e1 \u0111\u00e3 \u0111i\u1ec1u ch\u1ec9nh v\u00e0 ch\u01b0a \u0111i\u1ec1u ch\u1ec9nh, c\u1eeda s\u1ed5 \u01b0\u1edbc l\u01b0\u1ee3ng v\u00e0 c\u1eeda s\u1ed5 s\u1ef1 ki\u1ec7n, m\u00f4 h\u00ecnh chu\u1ea9n, c\u00f9ng c\u00e1c \u0111\u1eb7c th\u00f9 c\u1ee7a Vi\u1ec7t Nam nh\u01b0 bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng 7% tr\u00ean HOSE, 10% tr\u00ean HNX v\u00e0 15% tr\u00ean UPCoM (theo quy ch\u1ebf giao d\u1ecbch c\u1ee7a HOSE v\u00e0 HNX, t\u00ednh \u0111\u1ebfn th\u00e1ng 7\/2026).<\/p>\n\n\n<\/div>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"683\" src=\"https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/image-1-1024x683.png\" alt=\"Quy tr\u00ecnh chu\u1ea9n b\u1ecb d\u1eef li\u1ec7u cho Event Study tr\u00ean th\u1ecb tr\u01b0\u1eddng ch\u1ee9ng kho\u00e1n Vi\u1ec7t Nam\" class=\"wp-image-2619\" srcset=\"https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/image-1-1024x683.png 1024w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/image-1-300x200.png 300w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/image-1-768x512.png 768w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/image-1-18x12.png 18w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/image-1.png 1536w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"toc\">M\u1ee5c l\u1ee5c<\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li><a href=\"#what-is\">Event Study l\u00e0 g\u00ec v\u00e0 v\u00ec sao c\u00f3 series n\u00e0y?<\/a><\/li><li><a href=\"#model-myth\">V\u00ec sao ai c\u0169ng ngh\u0129 ph\u1ea7n kh\u00f3 nh\u1ea5t n\u1eb1m \u1edf m\u00f4 h\u00ecnh?<\/a><\/li><li><a href=\"#dividend-trap\">C\u00e1i b\u1eaby \u00e2m 16,7%: khi c\u1ed5 t\u1ee9c b\u1eb1ng c\u1ed5 phi\u1ebfu \u0111\u00e1nh l\u1eeba m\u00f4 h\u00ecnh<\/a><\/li><li><a href=\"#which-price\">N\u00ean d\u00f9ng m\u1ee9c gi\u00e1 n\u00e0o \u0111\u1ec3 t\u00ednh l\u1ee3i su\u1ea5t?<\/a><\/li><li><a href=\"#windows\">Ch\u1ecdn c\u1eeda s\u1ed5 \u01b0\u1edbc l\u01b0\u1ee3ng v\u00e0 c\u1eeda s\u1ed5 s\u1ef1 ki\u1ec7n nh\u01b0 th\u1ebf n\u00e0o?<\/a><\/li><li><a href=\"#benchmark\">M\u00f4 h\u00ecnh chu\u1ea9n n\u00e0o ph\u00f9 h\u1ee3p cho Event Study t\u1ea1i Vi\u1ec7t Nam?<\/a><\/li><li><a href=\"#vietnam-pitfalls\">Nh\u1eefng c\u1ea1m b\u1eaby \u0111\u1eb7c th\u00f9 n\u00e0o c\u1ee7a Vi\u1ec7t Nam l\u00e0m sai l\u1ec7ch m\u1ed9t Event Study?<\/a><\/li><li><a href=\"#datacore-data\">B\u1ed9 d\u1eef li\u1ec7u Historical Price c\u1ee7a DataCore h\u1ed7 tr\u1ee3 ra sao?<\/a><\/li><li><a href=\"#series-next\">Series n\u00e0y s\u1ebd \u0111i ti\u1ebfp v\u1ec1 \u0111\u00e2u?<\/a><\/li><li><a href=\"#faq\">C\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p<\/a><\/li><li><a href=\"#sources\">Ngu\u1ed3n tham kh\u1ea3o<\/a><\/li><\/ul>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"what-is\">Event Study l\u00e0 g\u00ec v\u00e0 v\u00ec sao c\u00f3 series n\u00e0y?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Event Study (nghi\u00ean c\u1ee9u s\u1ef1 ki\u1ec7n) l\u00e0 ph\u01b0\u01a1ng ph\u00e1p nghi\u00ean c\u1ee9u \u0111\u1ecbnh l\u01b0\u1ee3ng \u0111o l\u01b0\u1eddng ph\u1ea3n \u1ee9ng c\u1ee7a gi\u00e1 ch\u1ee9ng kho\u00e1n tr\u01b0\u1edbc m\u1ed9t s\u1ef1 ki\u1ec7n c\u1ee5 th\u1ec3: c\u00f4ng b\u1ed1 k\u1ebft qu\u1ea3 kinh doanh, th\u00f4ng b\u00e1o c\u1ed5 t\u1ee9c, thay \u0111\u1ed5i r\u1ed5 ch\u1ec9 s\u1ed1 hay m\u1ed9t quy \u0111\u1ecbnh m\u1edbi. M\u1ed9t Event Study so s\u00e1nh l\u1ee3i su\u1ea5t th\u1ef1c t\u1ebf c\u1ee7a c\u1ed5 phi\u1ebfu quanh s\u1ef1 ki\u1ec7n v\u1edbi l\u1ee3i su\u1ea5t \u0111\u01b0\u1ee3c k\u1ef3 v\u1ecdng trong \u0111i\u1ec1u ki\u1ec7n b\u00ecnh th\u01b0\u1eddng, v\u00e0 g\u1ecdi ph\u1ea7n ch\u00eanh l\u1ec7ch l\u00e0 l\u1ee3i su\u1ea5t b\u1ea5t th\u01b0\u1eddng (Abnormal Return, AR).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">K\u1ef9 thu\u1eadt n\u00e0y \u0111\u01b0\u1ee3c khai sinh b\u1edfi Fama, Fisher, Jensen v\u00e0 Roll (1969) tr\u00ean t\u1ea1p ch\u00ed International Economic Review, c\u00f2n b\u00e0i t\u1ed5ng quan kinh \u0111i\u1ec3n l\u00e0 MacKinlay (1997), \"Event Studies in Economics and Finance\", \u0111\u0103ng tr\u00ean Journal of Economic Literature.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">B\u00e0i vi\u1ebft n\u00e0y m\u1edf \u0111\u1ea7u series c\u1ee7a DataCore v\u1ec1 vi\u1ec7c x\u00e2y d\u1ef1ng m\u1ed9t h\u1ec7 th\u1ed1ng Event Study ho\u00e0n ch\u1ec9nh cho th\u1ecb tr\u01b0\u1eddng ch\u1ee9ng kho\u00e1n Vi\u1ec7t Nam, bao ph\u1ee7 S\u1edf Giao d\u1ecbch Ch\u1ee9ng kho\u00e1n Th\u00e0nh ph\u1ed1 H\u1ed3 Ch\u00ed Minh (HOSE), S\u1edf Giao d\u1ecbch Ch\u1ee9ng kho\u00e1n H\u00e0 N\u1ed9i (HNX) v\u00e0 th\u1ecb tr\u01b0\u1eddng c\u00f4ng ty \u0111\u1ea1i ch\u00fang ch\u01b0a ni\u00eam y\u1ebft (UPCoM). Series \u0111i theo \u0111\u00fang tr\u00ecnh t\u1ef1 m\u00e0 m\u1ed9t h\u1ec7 th\u1ed1ng nghi\u00ean c\u1ee9u th\u1ef1c th\u1ee5 \u0111\u01b0\u1ee3c ph\u00e1t tri\u1ec3n: hi\u1ec3u d\u1eef li\u1ec7u, x\u1eed l\u00fd d\u1eef li\u1ec7u, t\u00ednh l\u1ee3i su\u1ea5t, x\u00e2y d\u1ef1ng l\u1ee3i su\u1ea5t th\u1ecb tr\u01b0\u1eddng, v\u00e0 cu\u1ed1i c\u00f9ng l\u00e0 t\u00ednh l\u1ee3i su\u1ea5t b\u1ea5t th\u01b0\u1eddng.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Vi\u1ec7t Nam kh\u00f4ng thi\u1ebfu s\u1ef1 ki\u1ec7n \u0111\u00e1ng nghi\u00ean c\u1ee9u, t\u1eeb vi\u1ec7c <a href=\"https:\/\/blog.datacore.vn\/vi\/viet-nam-nang-hang-ftse-2026\/\">FTSE Russell n\u00e2ng h\u1ea1ng Vi\u1ec7t Nam l\u00ean th\u1ecb tr\u01b0\u1eddng m\u1edbi n\u1ed5i th\u1ee9 c\u1ea5p<\/a> \u0111\u1ebfn c\u00e1c thay \u0111\u1ed5i ch\u00ednh s\u00e1ch nh\u01b0 <a href=\"https:\/\/blog.datacore.vn\/vi\/thong-tu-25-2026\/\">Th\u00f4ng t\u01b0 25\/2026 v\u1ec1 thanh kho\u1ea3n ng\u00e2n h\u00e0ng<\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u00ec sao m\u1ed9t series v\u1ec1 m\u00f4 h\u00ecnh h\u00f3a l\u1ea1i m\u1edf \u0111\u1ea7u b\u1eb1ng m\u1ed9t b\u00e0i d\u00e0i v\u1ec1 d\u1eef li\u1ec7u? B\u1edfi trong Event Study, m\u00f4 h\u00ecnh hi\u1ebfm khi l\u00e0 n\u01a1i d\u1ef1 \u00e1n th\u1ea5t b\u1ea1i. D\u1eef li\u1ec7u m\u1edbi l\u00e0 n\u01a1i \u0111\u00f3. To\u00e0n b\u1ed9 ph\u1ea7n c\u00f2n l\u1ea1i c\u1ee7a b\u00e0i vi\u1ebft l\u00e0 l\u1eadp lu\u1eadn cho nh\u1eadn \u0111\u1ecbnh n\u00e0y, d\u1ef1a tr\u00ean th\u1ef1c t\u1ebf d\u1eef li\u1ec7u th\u1ecb tr\u01b0\u1eddng Vi\u1ec7t Nam.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"model-myth\">V\u00ec sao ai c\u0169ng ngh\u0129 ph\u1ea7n kh\u00f3 nh\u1ea5t n\u1eb1m \u1edf m\u00f4 h\u00ecnh?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00f3 m\u1ed9t \u0111i\u1ec1u kh\u00e1 th\u00fa v\u1ecb khi t\u00ecm hi\u1ec3u v\u1ec1 Event Study. Ph\u1ea7n l\u1edbn t\u00e0i li\u1ec7u \u0111\u1ec1u m\u1edf \u0111\u1ea7u b\u1eb1ng nh\u1eefng kh\u00e1i ni\u1ec7m quen thu\u1ed9c: Market Model, m\u00f4 h\u00ecnh \u0111\u1ecbnh gi\u00e1 t\u00e0i s\u1ea3n v\u1ed1n (CAPM), m\u00f4 h\u00ecnh ba nh\u00e2n t\u1ed1 c\u1ee7a Fama v\u00e0 French, Abnormal Return. Ch\u1ec9 c\u1ea7n g\u00f5 t\u1eeb kh\u00f3a t\u00ecm ki\u1ebfm, ng\u01b0\u1eddi \u0111\u1ecdc s\u1ebd nhanh ch\u00f3ng b\u1eaft g\u1eb7p h\u00e0ng lo\u1ea1t c\u00f4ng th\u1ee9c h\u1ed3i quy v\u00e0 ki\u1ec3m \u0111\u1ecbnh th\u1ed1ng k\u00ea. \u0110i\u1ec1u \u0111\u00f3 d\u1ec5 t\u1ea1o ra c\u1ea3m gi\u00e1c r\u1eb1ng ph\u1ea7n kh\u00f3 nh\u1ea5t n\u1eb1m \u1edf vi\u1ec7c l\u1ef1a ch\u1ecdn m\u00f4 h\u00ecnh.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Th\u1ef1c t\u1ebf l\u1ea1i kh\u00f4ng h\u1eb3n nh\u01b0 v\u1eady. Tr\u01b0\u1edbc khi m\u1ed9t \u0111\u01b0\u1eddng h\u1ed3i quy \u0111\u01b0\u1ee3c x\u00e2y d\u1ef1ng, tr\u01b0\u1edbc khi m\u1ed9t h\u1ec7 s\u1ed1 beta \u0111\u01b0\u1ee3c \u01b0\u1edbc l\u01b0\u1ee3ng hay m\u1ed9t l\u1ee3i su\u1ea5t b\u1ea5t th\u01b0\u1eddng \u0111\u01b0\u1ee3c t\u00ednh to\u00e1n, lu\u00f4n c\u00f3 m\u1ed9t b\u01b0\u1edbc kh\u00e1c \u00e2m th\u1ea7m \u0111\u1ee9ng ph\u00eda sau: chu\u1ea9n b\u1ecb d\u1eef li\u1ec7u. V\u00e0 g\u1ea7n nh\u01b0 m\u1ecdi th\u1ee9 trong m\u1ed9t Event Study \u0111\u1ec1u b\u1eaft \u0111\u1ea7u t\u1eeb d\u1eef li\u1ec7u gi\u00e1 l\u1ecbch s\u1eed (Historical Price).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Khi nh\u1eafc \u0111\u1ebfn d\u1eef li\u1ec7u gi\u00e1 c\u1ed5 phi\u1ebfu, nhi\u1ec1u ng\u01b0\u1eddi th\u01b0\u1eddng h\u00ecnh dung m\u1ed9t b\u1ea3ng d\u1eef li\u1ec7u kh\u00e1 \u0111\u01a1n gi\u1ea3n: ng\u00e0y giao d\u1ecbch, gi\u00e1 m\u1edf c\u1eeda, gi\u00e1 cao nh\u1ea5t, gi\u00e1 th\u1ea5p nh\u1ea5t, gi\u00e1 \u0111\u00f3ng c\u1eeda, kh\u1ed1i l\u01b0\u1ee3ng giao d\u1ecbch. Nh\u00ecn t\u1eeb g\u00f3c \u0111\u1ed9 tr\u1ef1c quan, \u0111i\u1ec1u \u0111\u00f3 \u0111\u1ee7 ch\u00ednh x\u00e1c. Nh\u01b0ng khi d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c \u0111\u01b0a v\u00e0o nghi\u00ean c\u1ee9u \u0111\u1ecbnh l\u01b0\u1ee3ng, \u0111\u1eb7c bi\u1ec7t l\u00e0 m\u1ed9t Event Study, b\u1ee9c tranh \u0111\u01a1n gi\u1ea3n \u1ea5y nhanh ch\u00f3ng ch\u1ea1m t\u1edbi gi\u1edbi h\u1ea1n.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"dividend-trap\">C\u00e1i b\u1eaby \u00e2m 16,7%: khi c\u1ed5 t\u1ee9c b\u1eb1ng c\u1ed5 phi\u1ebfu \u0111\u00e1nh l\u1eeba m\u00f4 h\u00ecnh<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Gi\u1ea3 s\u1eed gi\u00e1 \u0111\u00f3ng c\u1eeda c\u1ee7a m\u1ed9t c\u1ed5 phi\u1ebfu v\u00e0o ng\u00e0y T-1 l\u00e0 100.000 VND. Sang ng\u00e0y T, doanh nghi\u1ec7p chia c\u1ed5 t\u1ee9c b\u1eb1ng c\u1ed5 phi\u1ebfu t\u1ef7 l\u1ec7 20%: c\u1ee9 100 c\u1ed5 phi\u1ebfu \u0111ang n\u1eafm gi\u1eef, nh\u00e0 \u0111\u1ea7u t\u01b0 nh\u1eadn th\u00eam 20 c\u1ed5 phi\u1ebfu m\u1edbi. Theo quy t\u1eafc \u0111i\u1ec1u ch\u1ec9nh chu\u1ea9n c\u1ee7a c\u00e1c s\u1edf giao d\u1ecbch Vi\u1ec7t Nam, gi\u00e1 tham chi\u1ebfu ng\u00e0y T \u0111\u01b0\u1ee3c \u0111i\u1ec1u ch\u1ec9nh xu\u1ed1ng c\u00f2n kho\u1ea3ng 83.333 VND (100.000 chia cho 1,2).<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">N\u1ebfu t\u00ednh l\u1ee3i su\u1ea5t theo c\u00f4ng th\u1ee9c th\u00f4ng th\u01b0\u1eddng, so s\u00e1nh gi\u00e1 \u0111\u00f3ng c\u1eeda ng\u00e0y T v\u1edbi gi\u00e1 \u0111\u00f3ng c\u1eeda ch\u01b0a \u0111i\u1ec1u ch\u1ec9nh c\u1ee7a ng\u00e0y T-1, k\u1ebft qu\u1ea3 s\u1ebd l\u00e0 m\u1ed9t c\u00fa gi\u1ea3m g\u1ea7n \u00e2m 16,7%. Nh\u01b0ng t\u1ed5ng gi\u00e1 tr\u1ecb n\u1eafm gi\u1eef c\u1ee7a nh\u00e0 \u0111\u1ea7u t\u01b0 ho\u00e0n to\u00e0n kh\u00f4ng suy gi\u1ea3m; h\u1ecd ch\u1ec9 \u0111\u01a1n gi\u1ea3n n\u1eafm nhi\u1ec1u c\u1ed5 phi\u1ebfu h\u01a1n v\u1edbi m\u1ee9c gi\u00e1 th\u1ea5p h\u01a1n t\u01b0\u01a1ng \u1ee9ng. \u0110\u00e2y kh\u00f4ng ph\u1ea3i bi\u1ebfn \u0111\u1ed9ng th\u1ecb tr\u01b0\u1eddng th\u1eadt. \u0110\u00e2y l\u00e0 h\u1ec7 qu\u1ea3 c\u01a1 h\u1ecdc c\u1ee7a vi\u1ec7c t\u0103ng s\u1ed1 l\u01b0\u1ee3ng c\u1ed5 phi\u1ebfu l\u01b0u h\u00e0nh.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/candlestick-chart-event-study-1024x576.png\" alt=\"Bi\u1ec3u \u0111\u1ed3 n\u1ebfn gi\u00e1 c\u1ed5 phi\u1ebfu theo ng\u00e0y d\u00f9ng trong m\u1ed9t Event Study\" class=\"wp-image-2699\" srcset=\"https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/candlestick-chart-event-study-1024x576.png 1024w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/candlestick-chart-event-study-300x169.png 300w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/candlestick-chart-event-study-768x432.png 768w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/candlestick-chart-event-study-18x10.png 18w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/candlestick-chart-event-study.png 1280w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u01b0a chu\u1ed7i l\u1ee3i su\u1ea5t ch\u01b0a \u0111i\u1ec1u ch\u1ec9nh \u0111\u00f3 th\u1eb3ng v\u00e0o m\u1ed9t Event Study, ng\u00e0y T s\u1ebd b\u1ecb h\u1ec7 th\u1ed1ng g\u1eafn nh\u00e3n l\u00e0 m\u1ed9t c\u00fa s\u1ed1c gi\u00e1 ti\u00eau c\u1ef1c nghi\u00eam tr\u1ecdng, trong khi th\u1ef1c t\u1ebf kh\u00f4ng c\u00f3 s\u1ef1 ki\u1ec7n th\u1ecb tr\u01b0\u1eddng n\u00e0o x\u1ea3y ra. V\u1edbi m\u1ed9t Event Study m\u00e0 m\u1ee5c ti\u00eau duy nh\u1ea5t l\u00e0 b\u00f3c t\u00e1ch ph\u1ea3n \u1ee9ng gi\u00e1 th\u1eadt c\u1ee7a th\u1ecb tr\u01b0\u1eddng tr\u01b0\u1edbc s\u1ef1 ki\u1ec7n, m\u1ed9t sai l\u1ec7ch c\u1ee1 n\u00e0y khi\u1ebfn to\u00e0n b\u1ed9 k\u1ebft lu\u1eadn tr\u1edf n\u00ean v\u00f4 ngh\u0129a.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">C\u1ed5 t\u1ee9c b\u1eb1ng c\u1ed5 phi\u1ebfu v\u00e0 ph\u00e1t h\u00e0nh c\u1ed5 phi\u1ebfu th\u01b0\u1edfng l\u00e0 nh\u1eefng nghi\u1ec7p v\u1ee5 r\u1ea5t ph\u1ed5 bi\u1ebfn \u1edf doanh nghi\u1ec7p ni\u00eam y\u1ebft Vi\u1ec7t Nam, n\u00ean \u0111\u00e2y kh\u00f4ng ph\u1ea3i tr\u01b0\u1eddng h\u1ee3p c\u00e1 bi\u1ec7t c\u00f3 th\u1ec3 b\u1ecf qua; n\u00f3 l\u00e0 \u0111\u1eb7c \u0111i\u1ec3m l\u1eb7p \u0111i l\u1eb7p l\u1ea1i c\u1ee7a b\u1ed9 d\u1eef li\u1ec7u.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"which-price\">N\u00ean d\u00f9ng m\u1ee9c gi\u00e1 n\u00e0o \u0111\u1ec3 t\u00ednh l\u1ee3i su\u1ea5t?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1edbi m\u1ed9t Event Study, y\u00eau c\u1ea7u \u0111\u1ea7u ti\u00ean l\u00e0 chu\u1ed7i l\u1ee3i su\u1ea5t c\u1ee7a t\u1eebng c\u1ed5 phi\u1ebfu. V\u00e0 \u0111\u1ec3 t\u00ednh \u0111\u01b0\u1ee3c chu\u1ed7i \u0111\u00f3, m\u1ed9t c\u00e2u h\u1ecfi t\u01b0\u1edfng ch\u1eebng \u0111\u01a1n gi\u1ea3n xu\u1ea5t hi\u1ec7n ngay l\u1eadp t\u1ee9c: n\u00ean d\u00f9ng m\u1ee9c gi\u00e1 n\u00e0o? Gi\u00e1 \u0111\u00f3ng c\u1eeda th\u00f4, gi\u00e1 tham chi\u1ebfu c\u1ee7a s\u1edf giao d\u1ecbch, hay m\u1ee9c gi\u00e1 \u0111\u00e3 \u0111\u01b0\u1ee3c \u0111i\u1ec1u ch\u1ec9nh cho c\u00e1c s\u1ef1 ki\u1ec7n nh\u01b0 chia c\u1ed5 t\u1ee9c ti\u1ec1n m\u1eb7t, c\u1ed5 t\u1ee9c b\u1eb1ng c\u1ed5 phi\u1ebfu ho\u1eb7c ph\u00e1t h\u00e0nh th\u00eam?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">M\u1ed9t l\u1ef1a ch\u1ecdn t\u01b0\u1edfng nh\u01b0 nh\u1ecf \u1edf b\u01b0\u1edbc \u0111\u1ea7u ti\u00ean n\u00e0y, nh\u01b0 v\u00ed d\u1ee5 c\u1ed5 t\u1ee9c b\u1eb1ng c\u1ed5 phi\u1ebfu \u1edf tr\u00ean, c\u00f3 th\u1ec3 \u0111\u1ecbnh h\u00ecnh to\u00e0n b\u1ed9 k\u1ebft qu\u1ea3 c\u1ee7a nghi\u00ean c\u1ee9u. \u0110\u00f3 c\u0169ng l\u00e0 l\u00fd do c\u00e1c nghi\u00ean c\u1ee9u ph\u00e2n t\u00edch c\u00f9ng m\u1ed9t s\u1ef1 ki\u1ec7n c\u00f3 th\u1ec3 cho ra k\u1ebft qu\u1ea3 kh\u00e1c nhau. Kh\u00f4ng ph\u1ea3i v\u00ec m\u00f4 h\u00ecnh kh\u00e1c nhau, m\u00e0 v\u00ec d\u1eef li\u1ec7u \u0111\u1ea7u v\u00e0o \u0111\u00e3 kh\u00e1c nhau ngay t\u1eeb \u0111\u1ea7u.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u00e0 gi\u00e1 ch\u1ec9 l\u00e0 c\u00e2u h\u1ecfi \u0111\u1ea7u ti\u00ean trong r\u1ea5t nhi\u1ec1u c\u00e2u h\u1ecfi c\u1ea7n tr\u1ea3 l\u1eddi tr\u01b0\u1edbc khi b\u1ea5t k\u1ef3 ph\u00e9p t\u00ednh n\u00e0o b\u1eaft \u0111\u1ea7u. Kh\u1ed1i l\u01b0\u1ee3ng giao d\u1ecbch n\u00ean l\u1ea5y t\u1eeb kh\u1edbp l\u1ec7nh li\u00ean t\u1ee5c hay bao g\u1ed3m c\u1ea3 giao d\u1ecbch th\u1ecfa thu\u1eadn? M\u1ed9t giao d\u1ecbch th\u1ecfa thu\u1eadn quy m\u00f4 l\u1edbn gi\u1eefa hai c\u1ed5 \u0111\u00f4ng li\u00ean quan c\u00f3 th\u1ec3 th\u1ed5i ph\u1ed3ng kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a c\u1ea3 phi\u00ean m\u00e0 kh\u00f4ng ph\u1ea3n \u00e1nh b\u1ea5t k\u1ef3 d\u00f2ng ti\u1ec1n m\u1edbi hay thay \u0111\u1ed5i t\u00e2m l\u00fd th\u1ecb tr\u01b0\u1eddng n\u00e0o.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">N\u1ebfu m\u1ee5c ti\u00eau l\u00e0 nghi\u00ean c\u1ee9u h\u00e0nh vi nh\u00e0 \u0111\u1ea7u t\u01b0 n\u01b0\u1edbc ngo\u00e0i quanh s\u1ef1 ki\u1ec7n, n\u00ean d\u00f9ng chu\u1ed7i n\u00e0o: kh\u1ed1i l\u01b0\u1ee3ng mua b\u00e1n r\u00f2ng c\u1ee7a kh\u1ed1i ngo\u1ea1i, hay bi\u1ebfn \u0111\u1ed9ng c\u1ee7a ph\u1ea7n room ngo\u1ea1i c\u00f2n l\u1ea1i? Ch\u1ec9 khi b\u1eaft tay truy t\u00ecm c\u00e2u tr\u1ea3 l\u1eddi cho nh\u1eefng c\u00e2u h\u1ecfi t\u01b0\u1edfng nh\u1ecf n\u00e0y, ng\u01b0\u1eddi l\u00e0m Event Study m\u1edbi nh\u1eadn ra b\u1ea3ng gi\u00e1 l\u1ecbch s\u1eed ch\u01b0a bao gi\u1edd ch\u1ec9 l\u00e0 m\u1ed9t b\u1ea3ng gi\u00e1 \u0111\u01a1n gi\u1ea3n.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"windows\">Ch\u1ecdn c\u1eeda s\u1ed5 \u01b0\u1edbc l\u01b0\u1ee3ng v\u00e0 c\u1eeda s\u1ed5 s\u1ef1 ki\u1ec7n nh\u01b0 th\u1ebf n\u00e0o?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Khi chu\u1ed7i l\u1ee3i su\u1ea5t \u0111\u00e3 \u0111\u00e1ng tin, quy\u1ebft \u0111\u1ecbnh thi\u1ebft k\u1ebf ti\u1ebfp theo trong b\u1ea5t k\u1ef3 Event Study n\u00e0o l\u00e0 th\u1eddi gian. M\u1ed9t Event Study chia tr\u1ee5c th\u1eddi gian quanh m\u1ed7i s\u1ef1 ki\u1ec7n th\u00e0nh hai \u0111o\u1ea1n. C\u1eeda s\u1ed5 \u01b0\u1edbc l\u01b0\u1ee3ng (estimation window) l\u00e0 giai \u0111o\u1ea1n d\u00f9ng \u0111\u1ec3 h\u1ecdc xem l\u1ee3i su\u1ea5t \"b\u00ecnh th\u01b0\u1eddng\" c\u1ee7a c\u1ed5 phi\u1ebfu tr\u00f4ng nh\u01b0 th\u1ebf n\u00e0o. C\u1eeda s\u1ed5 s\u1ef1 ki\u1ec7n (event window) l\u00e0 giai \u0111o\u1ea1n \u0111o l\u01b0\u1eddng ph\u1ea3n \u1ee9ng c\u1ee7a th\u1ecb tr\u01b0\u1eddng tr\u01b0\u1edbc s\u1ef1 ki\u1ec7n.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">MacKinlay (1997, Journal of Economic Literature) m\u00f4 t\u1ea3 quy \u01b0\u1edbc ph\u1ed5 bi\u1ebfn cho d\u1eef li\u1ec7u ng\u00e0y: c\u1eeda s\u1ed5 \u01b0\u1edbc l\u01b0\u1ee3ng kho\u1ea3ng 120 \u0111\u1ebfn 250 phi\u00ean giao d\u1ecbch, k\u1ebft th\u00fac tr\u01b0\u1edbc khi c\u1eeda s\u1ed5 s\u1ef1 ki\u1ec7n b\u1eaft \u0111\u1ea7u, \u0111\u1ec3 b\u1ea3n th\u00e2n s\u1ef1 ki\u1ec7n kh\u00f4ng l\u00e0m nhi\u1ec5u \u01b0\u1edbc l\u01b0\u1ee3ng v\u1ec1 tr\u1ea1ng th\u00e1i b\u00ecnh th\u01b0\u1eddng. V\u1edbi c\u1eeda s\u1ed5 s\u1ef1 ki\u1ec7n, c\u00e1c nghi\u00ean c\u1ee9u th\u01b0\u1eddng b\u00e1o c\u00e1o nhi\u1ec1u \u0111\u1ed9 r\u1ed9ng kh\u00e1c nhau, ch\u1eb3ng h\u1ea1n t\u1eeb 1 phi\u00ean tr\u01b0\u1edbc \u0111\u1ebfn 1 phi\u00ean sau c\u00f4ng b\u1ed1, 5 phi\u00ean m\u1ed7i b\u00ean, ho\u1eb7c 10 phi\u00ean m\u1ed7i b\u00ean, nh\u1eb1m b\u1eaft c\u1ea3 hi\u1ec7n t\u01b0\u1ee3ng r\u00f2 r\u1ec9 th\u00f4ng tin tr\u01b0\u1edbc s\u1ef1 ki\u1ec7n l\u1eabn ph\u1ea3n \u1ee9ng tr\u1ec5 sau \u0111\u00f3.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>C\u1eeda s\u1ed5 \u01b0\u1edbc l\u01b0\u1ee3ng:<\/strong> \u0111\u1ee7 d\u00e0i \u0111\u1ec3 tham s\u1ed1 \u1ed5n \u0111\u1ecbnh, \u0111\u1ee7 ng\u1eafn \u0111\u1ec3 h\u1ed3 s\u01a1 r\u1ee7i ro c\u1ee7a doanh nghi\u1ec7p ch\u01b0a thay \u0111\u1ed5i c\u0103n b\u1ea3n. Kho\u1ea3ng 120 \u0111\u1ebfn 250 phi\u00ean l\u00e0 chu\u1ea9n m\u1ef1c s\u00e1ch gi\u00e1o khoa cho l\u1ee3i su\u1ea5t ng\u00e0y (MacKinlay, 1997).<\/li><li><strong>Kho\u1ea3ng \u0111\u1ec7m:<\/strong> nhi\u1ec1u thi\u1ebft k\u1ebf ch\u1eeba 5 \u0111\u1ebfn 10 phi\u00ean gi\u1eefa c\u1eeda s\u1ed5 \u01b0\u1edbc l\u01b0\u1ee3ng v\u00e0 c\u1eeda s\u1ed5 s\u1ef1 ki\u1ec7n \u0111\u1ec3 ph\u00f2ng r\u00f2 r\u1ec9 th\u00f4ng tin.<\/li><li><strong>C\u1eeda s\u1ed5 s\u1ef1 ki\u1ec7n:<\/strong> b\u1eaft \u0111\u1ea7u h\u1eb9p r\u1ed3i m\u1edf r\u1ed9ng d\u1ea7n. C\u1eeda s\u1ed5 qu\u00e1 r\u1ed9ng l\u00e0m lo\u00e3ng hi\u1ec7u \u1ee9ng v\u00e0 nhi\u1ec5m tin t\u1ee9c kh\u00f4ng li\u00ean quan; qu\u00e1 h\u1eb9p l\u1ea1i b\u1ecf s\u00f3t k\u1ef3 v\u1ecdng tr\u01b0\u1edbc s\u1ef1 ki\u1ec7n v\u00e0 \u0111\u1ed9 tr\u00f4i sau s\u1ef1 ki\u1ec7n.<\/li><li><strong>C\u1eeda s\u1ed5 sau s\u1ef1 ki\u1ec7n:<\/strong> d\u00f9ng khi c\u00e2u h\u1ecfi nghi\u00ean c\u1ee9u quan t\u00e2m t\u1edbi \u0111\u1ed9 tr\u00f4i d\u00e0i h\u1ea1n thay v\u00ec ph\u1ea3n \u1ee9ng t\u1ee9c th\u1eddi.<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Nh\u1eefng l\u1ef1a ch\u1ecdn n\u00e0y g\u1eafn ch\u1eb7t v\u1edbi c\u00e1c v\u1ea5n \u0111\u1ec1 d\u1eef li\u1ec7u \u1edf tr\u00ean. N\u1ebfu c\u1eeda s\u1ed5 \u01b0\u1edbc l\u01b0\u1ee3ng ch\u1ee9a m\u1ed9t c\u00fa nh\u1ea3y gi\u00e1 ch\u01b0a \u0111i\u1ec1u ch\u1ec9nh ki\u1ec3u \u00e2m 16,7%, h\u1ec7 s\u1ed1 beta v\u00e0 ph\u01b0\u01a1ng sai \u01b0\u1edbc l\u01b0\u1ee3ng \u0111\u01b0\u1ee3c \u0111\u1ec1u b\u1ecb \u00f4 nhi\u1ec5m, v\u00e0 m\u1ecdi l\u1ee3i su\u1ea5t b\u1ea5t th\u01b0\u1eddng t\u00ednh t\u1eeb ch\u00fang th\u1eeba h\u01b0\u1edfng sai s\u1ed1 \u0111\u00f3. Thi\u1ebft k\u1ebf c\u1eeda s\u1ed5 v\u00e0 chu\u1ea9n b\u1ecb d\u1eef li\u1ec7u kh\u00f4ng ph\u1ea3i hai ch\u01b0\u01a1ng t\u00e1ch bi\u1ec7t; ch\u00fang l\u00e0 c\u00f9ng m\u1ed9t ch\u01b0\u01a1ng.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"benchmark\">M\u00f4 h\u00ecnh chu\u1ea9n n\u00e0o ph\u00f9 h\u1ee3p cho Event Study t\u1ea1i Vi\u1ec7t Nam?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">L\u1ee3i su\u1ea5t b\u1ea5t th\u01b0\u1eddng lu\u00f4n \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a so v\u1edbi m\u1ed9t m\u00f4 h\u00ecnh chu\u1ea9n v\u1ec1 l\u1ee3i su\u1ea5t k\u1ef3 v\u1ecdng. Di\u1ec5n \u0111\u1ea1t b\u1eb1ng l\u1eddi: l\u1ee3i su\u1ea5t b\u1ea5t th\u01b0\u1eddng c\u1ee7a c\u1ed5 phi\u1ebfu i trong ng\u00e0y t b\u1eb1ng l\u1ee3i su\u1ea5t th\u1ef1c t\u1ebf c\u1ee7a c\u1ed5 phi\u1ebfu i trong ng\u00e0y t tr\u1eeb \u0111i l\u1ee3i su\u1ea5t m\u00e0 m\u00f4 h\u00ecnh chu\u1ea9n k\u1ef3 v\u1ecdng. Hai m\u00f4 h\u00ecnh chu\u1ea9n th\u00f4ng d\u1ee5ng nh\u1ea5t trong c\u00e1c Event Study \u0111\u1ec1u r\u1ea5t \u0111\u01a1n gi\u1ea3n.<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>M\u00f4 h\u00ecnh hi\u1ec7u ch\u1ec9nh theo th\u1ecb tr\u01b0\u1eddng (market-adjusted):<\/strong> l\u1ee3i su\u1ea5t k\u1ef3 v\u1ecdng b\u1eb1ng l\u1ee3i su\u1ea5t th\u1ecb tr\u01b0\u1eddng. Khi \u0111\u00f3 <em>AR<sub>it<\/sub><\/em> b\u1eb1ng <em>R<sub>it<\/sub><\/em> tr\u1eeb <em>R<sub>mt<\/sub><\/em>, v\u1edbi <em>R<sub>mt<\/sub><\/em> l\u00e0 l\u1ee3i su\u1ea5t c\u1ee7a m\u1ed9t ch\u1ec9 s\u1ed1 th\u1ecb tr\u01b0\u1eddng nh\u01b0 VN-Index.<\/li><li><strong>Market Model:<\/strong> l\u1ee3i su\u1ea5t k\u1ef3 v\u1ecdng b\u1eb1ng <em>alpha<sub>i<\/sub><\/em> c\u1ed9ng <em>beta<sub>i<\/sub><\/em> nh\u00e2n <em>R<sub>mt<\/sub><\/em>, trong \u0111\u00f3 alpha v\u00e0 beta \u0111\u01b0\u1ee3c \u01b0\u1edbc l\u01b0\u1ee3ng b\u1eb1ng h\u1ed3i quy b\u00ecnh ph\u01b0\u01a1ng nh\u1ecf nh\u1ea5t tr\u00ean c\u1eeda s\u1ed5 \u01b0\u1edbc l\u01b0\u1ee3ng. Khi \u0111\u00f3 <em>AR<sub>it<\/sub><\/em> b\u1eb1ng <em>R<sub>it<\/sub><\/em> tr\u1eeb (<em>alpha<sub>i<\/sub><\/em> c\u1ed9ng <em>beta<sub>i<\/sub><\/em> nh\u00e2n <em>R<sub>mt<\/sub><\/em>).<\/li><\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Brown v\u00e0 Warner (1985, Journal of Financial Economics) \u0111\u00e3 ch\u1ee9ng minh b\u1eb1ng m\u00f4 ph\u1ecfng tr\u00ean d\u1eef li\u1ec7u ng\u00e0y r\u1eb1ng c\u00e1c m\u00f4 h\u00ecnh chu\u1ea9n \u0111\u01a1n gi\u1ea3n n\u00e0y ph\u00e1t hi\u1ec7n l\u1ee3i su\u1ea5t b\u1ea5t th\u01b0\u1eddng t\u1ed1t kh\u00f4ng k\u00e9m c\u00e1c m\u00f4 h\u00ecnh ph\u1ee9c t\u1ea1p h\u01a1n nhi\u1ec1u. K\u1ebft qu\u1ea3 \u0111\u00f3 r\u1ea5t \u0111\u00e1ng gi\u00e1 v\u1edbi b\u1ea5t k\u1ef3 ai x\u00e2y d\u1ef1ng Event Study t\u1ea1i Vi\u1ec7t Nam: ph\u1ea7n l\u1ee3i \u00edch bi\u00ean n\u1eb1m \u1edf ch\u1ea5t l\u01b0\u1ee3ng d\u1eef li\u1ec7u, kh\u00f4ng n\u1eb1m \u1edf \u0111\u1ed9 c\u1ea7u k\u1ef3 c\u1ee7a m\u00f4 h\u00ecnh.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Vi\u1ec7t Nam v\u1eabn \u0111\u1eb7t th\u00eam hai c\u00e2u h\u1ecfi ri\u00eang v\u1ec1 m\u00f4 h\u00ecnh chu\u1ea9n. Th\u1ee9 nh\u1ea5t, ch\u1ec9 s\u1ed1 n\u00e0o \u0111\u1ea1i di\u1ec7n cho \"th\u1ecb tr\u01b0\u1eddng\": VN-Index cho c\u1ed5 phi\u1ebfu HOSE, HNX Index, hay m\u1ed9t ch\u1ec9 s\u1ed1 t\u1ed5ng h\u1ee3p r\u1ed9ng h\u01a1n? M\u1ed9t s\u1ef1 ki\u1ec7n ng\u00e0nh t\u00e0i ch\u00ednh \u0111\u01b0\u1ee3c so v\u1edbi m\u1ed9t ch\u1ec9 s\u1ed1 n\u1eb7ng c\u1ed5 phi\u1ebfu ng\u00e2n h\u00e0ng c\u00f3 th\u1ec3 tr\u00f4ng b\u00ecnh th\u01b0\u1eddng m\u1ed9t c\u00e1ch gi\u1ea3 t\u1ea1o.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Th\u1ee9 hai, thanh kho\u1ea3n m\u1ecfng. Nhi\u1ec1u m\u00e3 tr\u00ean HNX v\u00e0 UPCoM giao d\u1ecbch th\u01b0a th\u1edbt, v\u00e0 giao d\u1ecbch th\u01b0a l\u00e0m l\u1ec7ch \u01b0\u1edbc l\u01b0\u1ee3ng beta b\u1eb1ng b\u00ecnh ph\u01b0\u01a1ng nh\u1ecf nh\u1ea5t. C\u00e1c hi\u1ec7u ch\u1ec9nh kinh \u0111i\u1ec3n l\u00e0 \u01b0\u1edbc l\u01b0\u1ee3ng c\u1ee7a Scholes v\u00e0 Williams (1977) v\u00e0 Dimson (1979), d\u00f9ng \u0111\u1ed9 tr\u1ec5 v\u00e0 \u0111\u1ed9 s\u1edbm c\u1ee7a l\u1ee3i su\u1ea5t th\u1ecb tr\u01b0\u1eddng \u0111\u1ec3 s\u1eeda \u0111\u1ed9 l\u1ec7ch. M\u1ed9t Event Study b\u1ecf qua thanh kho\u1ea3n m\u1ecfng \u1edf c\u00e1c m\u00e3 nh\u1ecf c\u1ee7a Vi\u1ec7t Nam s\u1ebd \u01b0\u1edbc l\u01b0\u1ee3ng sai l\u1ee3i su\u1ea5t k\u1ef3 v\u1ecdng m\u1ed9t c\u00e1ch h\u1ec7 th\u1ed1ng.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"vietnam-pitfalls\">Nh\u1eefng c\u1ea1m b\u1eaby \u0111\u1eb7c th\u00f9 n\u00e0o c\u1ee7a Vi\u1ec7t Nam l\u00e0m sai l\u1ec7ch m\u1ed9t Event Study?<\/h2>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/hose-stock-exchange-hcmc-1024x576.jpg\" alt=\"T\u00f2a nh\u00e0 S\u1edf Giao d\u1ecbch Ch\u1ee9ng kho\u00e1n Th\u00e0nh ph\u1ed1 H\u1ed3 Ch\u00ed Minh (HOSE), Vi\u1ec7t Nam\" class=\"wp-image-2698\" srcset=\"https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/hose-stock-exchange-hcmc-1024x576.jpg 1024w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/hose-stock-exchange-hcmc-300x169.jpg 300w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/hose-stock-exchange-hcmc-768x432.jpg 768w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/hose-stock-exchange-hcmc-18x10.jpg 18w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/hose-stock-exchange-hcmc.jpg 1280w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Ngo\u00e0i chuy\u1ec7n \u0111i\u1ec1u ch\u1ec9nh nghi\u1ec7p v\u1ee5 doanh nghi\u1ec7p, vi c\u1ea5u tr\u00fac c\u1ee7a th\u1ecb tr\u01b0\u1eddng Vi\u1ec7t Nam t\u1ea1o ra v\u00e0i c\u00e1i b\u1eaby m\u00e0 c\u00f4ng th\u1ee9c s\u00e1ch gi\u00e1o khoa kh\u00f4ng nh\u1eafc t\u1edbi. B\u1ea5t k\u1ef3 ai ch\u1ea1y Event Study tr\u00ean d\u1eef li\u1ec7u HOSE, HNX hay UPCoM n\u00ean thi\u1ebft k\u1ebf quanh \u00edt nh\u1ea5t b\u1ed1n \u0111i\u1ec3m sau.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u1eaft c\u1ee5t l\u1ee3i su\u1ea5t<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00e1c s\u1edf giao d\u1ecbch Vi\u1ec7t Nam gi\u1edbi h\u1ea1n bi\u1ebfn \u0111\u1ed9ng ng\u00e0y quanh gi\u00e1 tham chi\u1ebfu: 7% m\u1ed7i chi\u1ec1u tr\u00ean HOSE, 10% tr\u00ean HNX v\u00e0 15% tr\u00ean UPCoM theo quy ch\u1ebf giao d\u1ecbch hi\u1ec7n h\u00e0nh (quy \u0111\u1ecbnh c\u1ee7a HOSE v\u00e0 HNX, t\u00ednh \u0111\u1ebfn th\u00e1ng 7\/2026). Bi\u00ean \u0111\u1ed9 r\u1ed9ng h\u01a1n \u00e1p d\u1ee5ng cho ng\u00e0y giao d\u1ecbch \u0111\u1ea7u ti\u00ean ho\u1eb7c sau khi b\u1ecb ng\u1eebng giao d\u1ecbch tr\u00ean 25 phi\u00ean: t\u1ed1i \u0111a 20% tr\u00ean HOSE, 30% tr\u00ean HNX v\u00e0 40% tr\u00ean UPCoM.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Khi tin t\u1ee9c \u0111\u1ee7 m\u1ea1nh, c\u1ed5 phi\u1ebfu c\u00f3 th\u1ec3 tr\u1ea7n ho\u1eb7c s\u00e0n nhi\u1ec1u phi\u00ean li\u00ean ti\u1ebfp v\u1edbi kh\u1ed1i l\u01b0\u1ee3ng kh\u1edbp g\u1ea7n nh\u01b0 b\u1eb1ng kh\u00f4ng. Ph\u1ea3n \u1ee9ng th\u1eadt khi \u0111\u00f3 b\u1ecb d\u00e0n m\u1ecfng qua nhi\u1ec1u ng\u00e0y, n\u00ean c\u1eeda s\u1ed5 s\u1ef1 ki\u1ec7n 1 phi\u00ean s\u1ebd \u0111\u00e1nh gi\u00e1 th\u1ea5p hi\u1ec7u \u1ee9ng m\u1ed9t c\u00e1ch c\u01a1 h\u1ecdc. Ng\u01b0\u1eddi nghi\u00ean c\u1ee9u n\u00ean m\u1edf r\u1ed9ng c\u1eeda s\u1ed5 v\u00e0 theo d\u00f5i r\u00f5 c\u00e1c chu\u1ed7i phi\u00ean ch\u1ea1m bi\u00ean \u0111\u1ed9.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Chu k\u1ef3 thanh to\u00e1n l\u00e0m l\u1ec7ch th\u1eddi \u0111i\u1ec3m giao d\u1ecbch \u0111\u01b0\u1ee3c<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">T\u1eeb ng\u00e0y 29\/8\/2022, T\u1ed5ng c\u00f4ng ty L\u01b0u k\u00fd v\u00e0 B\u00f9 tr\u1eeb Ch\u1ee9ng kho\u00e1n Vi\u1ec7t Nam (VSDC) ho\u00e0n t\u1ea5t thanh to\u00e1n c\u1ed5 phi\u1ebfu \u0111\u1ec3 ch\u1ee9ng kho\u00e1n v\u00e0 ti\u1ec1n v\u1ec1 t\u00e0i kho\u1ea3n tr\u01b0\u1edbc 13:00 ng\u00e0y T+2, cho ph\u00e9p nh\u00e0 \u0111\u1ea7u t\u01b0 giao d\u1ecbch ngay trong phi\u00ean chi\u1ec1u h\u00f4m \u0111\u00f3 (th\u00f4ng b\u00e1o VSDC; Vietnam News, 25\/8\/2022). Gi\u1edbi th\u1ef1c h\u00e0nh g\u1ecdi \u0111\u00e2y l\u00e0 chu k\u1ef3 T+2,5.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1edbi m\u1ed9t Event Study d\u00f9ng ph\u1ea3n \u1ee9ng kh\u1ed1i l\u01b0\u1ee3ng ho\u1eb7c d\u00f2ng l\u1ec7nh, \u0111i\u1ec1u n\u00e0y r\u1ea5t quan tr\u1ecdng: ng\u00e0y s\u1edbm nh\u1ea5t m\u00e0 ng\u01b0\u1eddi \u0111\u00e3 mua c\u00f3 th\u1ec3 ph\u1ea3n \u1ee9ng b\u1eb1ng c\u00e1ch b\u00e1n ra kh\u00f4ng ph\u1ea3i l\u00e0 ng\u00e0y s\u1ef1 ki\u1ec7n, v\u00e0 c\u00e1ch di\u1ec5n gi\u1ea3i hi\u1ec7u \u1ee9ng kh\u1ed1i l\u01b0\u1ee3ng qua c\u1eeda s\u1ed5 s\u1ef1 ki\u1ec7n ph\u1ea3i t\u00ednh \u0111\u1ebfn \u0111i\u1ec1u \u0111\u00f3.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">C\u1ea5u tr\u00fac phi\u00ean v\u00e0 giao d\u1ecbch th\u1ecfa thu\u1eadn l\u00e0m nhi\u1ec5u kh\u1ed1i l\u01b0\u1ee3ng<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Giao d\u1ecbch tr\u00ean HOSE \u0111i qua phi\u00ean kh\u1edbp l\u1ec7nh \u0111\u1ecbnh k\u1ef3 m\u1edf c\u1eeda (ATO), kh\u1edbp l\u1ec7nh li\u00ean t\u1ee5c v\u00e0 phi\u00ean kh\u1edbp l\u1ec7nh \u0111\u1ecbnh k\u1ef3 \u0111\u00f3ng c\u1eeda (ATC), song song v\u1edbi k\u00eanh th\u1ecfa thu\u1eadn ri\u00eang. Nh\u01b0 \u0111\u00e3 n\u00eau \u1edf tr\u00ean, m\u1ed9t l\u00f4 th\u1ecfa thu\u1eadn l\u1edbn gi\u1eefa c\u00e1c c\u1ed5 \u0111\u00f4ng li\u00ean quan c\u00f3 th\u1ec3 nh\u00e2n kh\u1ed1i l\u01b0\u1ee3ng b\u00e1o c\u00e1o c\u1ee7a c\u1ea3 phi\u00ean l\u00ean nhi\u1ec1u l\u1ea7n m\u00e0 t\u00e2m l\u00fd th\u1ecb tr\u01b0\u1eddng kh\u00f4ng h\u1ec1 thay \u0111\u1ed5i. C\u00e1c th\u01b0\u1edbc \u0111o kh\u1ed1i l\u01b0\u1ee3ng nghi\u00eam t\u00fac trong Event Study t\u00e1ch ri\u00eang kh\u1ed1i l\u01b0\u1ee3ng kh\u1edbp l\u1ec7nh kh\u1ecfi kh\u1ed1i l\u01b0\u1ee3ng th\u1ecfa thu\u1eadn, v\u00e0 \u0111\u00f3 ch\u00ednh l\u00e0 l\u00fd do b\u1ed9 d\u1eef li\u1ec7u g\u1ed1c ph\u1ea3i ghi nh\u1eadn ch\u00fang t\u00e1ch b\u1ea1ch.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Gi\u1edbi h\u1ea1n s\u1edf h\u1eefu n\u01b0\u1edbc ngo\u00e0i b\u00f3p m\u00e9o t\u00edn hi\u1ec7u d\u00f2ng v\u1ed1n ngo\u1ea1i<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Nhi\u1ec1u c\u1ed5 phi\u1ebfu Vi\u1ec7t Nam giao d\u1ecbch s\u00e1t ho\u1eb7c k\u00edn gi\u1edbi h\u1ea1n s\u1edf h\u1eefu n\u01b0\u1edbc ngo\u00e0i. Khi room \u0111\u00e3 \u0111\u1ea7y, kh\u1ed1i ngo\u1ea1i kh\u00f4ng th\u1ec3 mua tr\u00ean s\u00e0n d\u00f9 s\u1ef1 ki\u1ec7n t\u00edch c\u1ef1c \u0111\u1ebfn \u0111\u00e2u, n\u00ean gi\u00e1 tr\u1ecb mua r\u00f2ng c\u1ee7a kh\u1ed1i ngo\u1ea1i \u0111i ngang v\u00ec nh\u1eefng l\u00fd do kh\u00f4ng li\u00ean quan \u0111\u1ebfn t\u00e2m l\u00fd. M\u1ed9t Event Study v\u1ec1 h\u00e0nh vi nh\u00e0 \u0111\u1ea7u t\u01b0 n\u01b0\u1edbc ngo\u00e0i v\u00ec v\u1eady ph\u1ea3i \u0111\u1ecdc d\u00f2ng v\u1ed1n ngo\u1ea1i r\u00f2ng c\u00f9ng v\u1edbi ph\u1ea7n room c\u00f2n l\u1ea1i, kh\u00f4ng \u0111\u1ecdc t\u00e1ch r\u1eddi.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"datacore-data\">B\u1ed9 d\u1eef li\u1ec7u Historical Price c\u1ee7a DataCore h\u1ed7 tr\u1ee3 ra sao?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Trong vi\u1ec7c x\u00e2y d\u1ef1ng m\u1ed9t Event Study, d\u1eef li\u1ec7u gi\u00e1 l\u1ecbch s\u1eed l\u00e0 vi\u00ean g\u1ea1ch \u0111\u1ea7u ti\u00ean c\u1ee7a to\u00e0n b\u1ed9 h\u1ec7 th\u1ed1ng. M\u1ecdi th\u1ee9 ph\u00eda sau, chu\u1ed7i l\u1ee3i su\u1ea5t, l\u1ee3i su\u1ea5t th\u1ecb tr\u01b0\u1eddng, v\u00e0 cu\u1ed1i c\u00f9ng l\u00e0 l\u1ee3i su\u1ea5t b\u1ea5t th\u01b0\u1eddng, \u0111\u1ec1u \u0111\u01b0\u1ee3c x\u00e2y tr\u00ean n\u1ec1n \u0111\u00f3. Kh\u00f4ng m\u00f4 h\u00ecnh th\u1ed1ng k\u00ea n\u00e0o, d\u00f9 tinh vi \u0111\u1ebfn \u0111\u00e2u, c\u00f3 th\u1ec3 b\u00f9 \u0111\u1eafp cho d\u1eef li\u1ec7u \u0111\u1ea7u v\u00e0o thi\u1ebfu tin c\u1eady. \u0110\u00f3 l\u00e0 l\u00fd do series n\u00e0y kh\u00f4ng b\u1eaft \u0111\u1ea7u t\u1eeb c\u00e1c m\u00f4 h\u00ecnh t\u00e0i ch\u00ednh, v\u00e0 b\u00e0i vi\u1ebft \u0111\u1ea7u ti\u00ean \u0111\u01b0\u1ee3c d\u00e0nh tr\u1ecdn cho ph\u1ea7n n\u1ec1n m\u00f3ng.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Xuy\u00ean su\u1ed1t series, d\u1eef li\u1ec7u \u0111\u01b0\u1ee3c l\u1ea5y t\u1eeb <a href=\"https:\/\/datacore.vn\/en\/get-data\/data-domains\/market\/dataset-groups\/5\" target=\"_blank\" rel=\"noopener\">b\u1ed9 d\u1eef li\u1ec7u Historical Price tr\u00ean n\u1ec1n t\u1ea3ng DataCore<\/a>. B\u1ed9 d\u1eef li\u1ec7u n\u00e0y kh\u00f4ng ch\u1ec9 l\u01b0u gi\u00e1 giao d\u1ecbch h\u1eb1ng ng\u00e0y c\u1ee7a c\u1ed5 phi\u1ebfu ni\u00eam y\u1ebft tr\u00ean HOSE, HNX v\u00e0 UPCoM. N\u00f3 c\u00f2n bao g\u1ed3m gi\u00e1 tham chi\u1ebfu, h\u1ec7 s\u1ed1 \u0111i\u1ec1u ch\u1ec9nh gi\u00e1 theo c\u00e1c s\u1ef1 ki\u1ec7n nghi\u1ec7p v\u1ee5 doanh nghi\u1ec7p, kh\u1ed1i l\u01b0\u1ee3ng v\u00e0 gi\u00e1 tr\u1ecb t\u00e1ch ri\u00eang theo kh\u1edbp l\u1ec7nh v\u00e0 th\u1ecfa thu\u1eadn, c\u00f9ng d\u1eef li\u1ec7u mua b\u00e1n v\u00e0 room s\u1edf h\u1eefu c\u1ee7a nh\u00e0 \u0111\u1ea7u t\u01b0 n\u01b0\u1edbc ngo\u00e0i.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u0110\u00e2y ch\u00ednh x\u00e1c l\u00e0 nh\u1eefng tr\u01b0\u1eddng d\u1eef li\u1ec7u m\u00e0 series s\u1ebd khai th\u00e1c: kh\u00f4ng ph\u1ea3i \u0111\u1ec3 v\u1ebd bi\u1ec3u \u0111\u1ed3, m\u00e0 \u0111\u1ec3 t\u00ednh l\u1ee3i su\u1ea5t cho \u0111\u00fang, x\u1eed l\u00fd c\u00e1c s\u1ef1 ki\u1ec7n \u0111i\u1ec1u ch\u1ec9nh gi\u00e1, v\u00e0 b\u00f3c t\u00e1ch d\u00f2ng v\u1ed1n ngo\u1ea1i m\u1ed7i khi b\u00e0i to\u00e1n c\u1ee5 th\u1ec3 y\u00eau c\u1ea7u. M\u1ed7i c\u1ea1m b\u1eaby \u1edf ph\u1ea7n tr\u01b0\u1edbc t\u01b0\u01a1ng \u1ee9ng v\u1edbi m\u1ed9t tr\u01b0\u1eddng c\u1ee5 th\u1ec3 trong b\u1ed9 d\u1eef li\u1ec7u, v\u00e0 \u0111\u00f3 l\u00e0 ph\u00e9p th\u1eed th\u1ef1c t\u1ebf cho c\u00e2u h\u1ecfi m\u1ed9t ngu\u1ed3n d\u1eef li\u1ec7u \u0111\u00e3 s\u1eb5n s\u00e0ng cho nghi\u00ean c\u1ee9u Event Study hay ch\u01b0a.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"series-next\">Series n\u00e0y s\u1ebd \u0111i ti\u1ebfp v\u1ec1 \u0111\u00e2u?<\/h2>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"819\" height=\"1024\" src=\"https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/image-819x1024.png\" alt=\"C\u1ea5u tr\u00fac b\u1ed9 d\u1eef li\u1ec7u gi\u00e1 l\u1ecbch s\u1eed \u0111\u1ee9ng sau series Event Study\" class=\"wp-image-2618\" srcset=\"https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/image-819x1024.png 819w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/image-240x300.png 240w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/image-768x960.png 768w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/image-10x12.png 10w, https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/image.png 1122w\" sizes=\"auto, (max-width: 819px) 100vw, 819px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Series n\u00e0y \u0111\u01b0\u1ee3c x\u00e2y d\u1ef1ng theo \u0111\u00fang tr\u00ecnh t\u1ef1 m\u00e0 m\u1ed9t h\u1ec7 th\u1ed1ng Event Study th\u1ef1c th\u1ee5 \u0111\u01b0\u1ee3c ph\u00e1t tri\u1ec3n. Thay v\u00ec b\u1eaft \u0111\u1ea7u b\u1eb1ng c\u00f4ng th\u1ee9c, m\u1ed7i b\u00e0i vi\u1ebft gi\u1ea3i quy\u1ebft m\u1ed9t b\u00e0i to\u00e1n c\u1ee5 th\u1ec3: hi\u1ec3u d\u1eef li\u1ec7u, x\u1eed l\u00fd d\u1eef li\u1ec7u, t\u00ednh l\u1ee3i su\u1ea5t, x\u00e2y d\u1ef1ng l\u1ee3i su\u1ea5t th\u1ecb tr\u01b0\u1eddng, v\u00e0 ho\u00e0n thi\u1ec7n to\u00e0n b\u1ed9 quy tr\u00ecnh t\u00ednh l\u1ee3i su\u1ea5t b\u1ea5t th\u01b0\u1eddng c\u00f9ng c\u00e1c ki\u1ec3m \u0111\u1ecbnh \u00fd ngh\u0129a th\u1ed1ng k\u00ea.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Hy v\u1ecdng \u0111\u1ebfn cu\u1ed1i series, b\u1ea1n \u0111\u1ecdc kh\u00f4ng ch\u1ec9 bi\u1ebft c\u00e1ch ch\u1ea1y m\u1ed9t Event Study. B\u1ea1n s\u1ebd hi\u1ec3u v\u00ec sao t\u1eebng b\u01b0\u1edbc trong quy tr\u00ecnh t\u1ed3n t\u1ea1i, v\u00e0 d\u1eef li\u1ec7u \u0111\u00e3 \u0111\u1ecbnh h\u00ecnh k\u1ebft qu\u1ea3 cu\u1ed1i c\u00f9ng nh\u01b0 th\u1ebf n\u00e0o ngay t\u1eeb \u0111\u1ea7u. B\u00e0i ti\u1ebfp theo quay l\u1ea1i ch\u00ednh b\u1ed9 d\u1eef li\u1ec7u Historical Price. Thay v\u00ec xem n\u00f3 nh\u01b0 m\u1ed9t b\u1ea3ng gi\u00e1 c\u1ed5 phi\u1ebfu, b\u00e0i vi\u1ebft s\u1ebd \u0111i v\u00e0o t\u1eebng nh\u00f3m th\u00f4ng tin b\u00ean trong, gi\u1ea3i ngh\u0129a t\u1eebng tr\u01b0\u1eddng d\u1eef li\u1ec7u, v\u00e0 l\u00fd gi\u1ea3i v\u00ec sao m\u1ed9t b\u1ed9 d\u1eef li\u1ec7u gi\u00e1 l\u1ecbch s\u1eed \u0111\u1ea7y \u0111\u1ee7 l\u00e0 ranh gi\u1edbi gi\u1eefa m\u1ed9t Event Study v\u1eefng ch\u1eafc v\u00e0 m\u1ed9t nghi\u00ean c\u1ee9u g\u00e2y hi\u1ec3u l\u1ea7m.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"faq\">C\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Event Study trong t\u00e0i ch\u00ednh l\u00e0 g\u00ec?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Event Study l\u00e0 ph\u01b0\u01a1ng ph\u00e1p th\u1ed1ng k\u00ea \u0111o l\u01b0\u1eddng t\u00e1c \u0111\u1ed9ng c\u1ee7a m\u1ed9t s\u1ef1 ki\u1ec7n c\u1ee5 th\u1ec3 l\u00ean gi\u00e1 tr\u1ecb c\u1ee7a ch\u1ee9ng kho\u00e1n. Event Study so s\u00e1nh l\u1ee3i su\u1ea5t th\u1ef1c t\u1ebf quanh s\u1ef1 ki\u1ec7n v\u1edbi l\u1ee3i su\u1ea5t m\u00e0 m\u00f4 h\u00ecnh chu\u1ea9n k\u1ef3 v\u1ecdng, v\u00e0 di\u1ec5n gi\u1ea3i ph\u1ea7n ch\u00eanh l\u1ec7ch, t\u1ee9c l\u1ee3i su\u1ea5t b\u1ea5t th\u01b0\u1eddng, l\u00e0 ph\u1ea3n \u1ee9ng c\u1ee7a th\u1ecb tr\u01b0\u1eddng tr\u01b0\u1edbc s\u1ef1 ki\u1ec7n. Khung ph\u01b0\u01a1ng ph\u00e1p b\u1eaft ngu\u1ed3n t\u1eeb Fama, Fisher, Jensen v\u00e0 Roll (1969) v\u00e0 \u0111\u01b0\u1ee3c t\u1ed5ng quan trong MacKinlay (1997).<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">C\u1eeda s\u1ed5 \u01b0\u1edbc l\u01b0\u1ee3ng n\u00ean d\u00e0i bao nhi\u00eau?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">V\u1edbi l\u1ee3i su\u1ea5t ng\u00e0y, quy \u01b0\u1edbc ph\u1ed5 bi\u1ebfn l\u00e0 kho\u1ea3ng 120 \u0111\u1ebfn 250 phi\u00ean giao d\u1ecbch, k\u1ebft th\u00fac tr\u01b0\u1edbc c\u1eeda s\u1ed5 s\u1ef1 ki\u1ec7n, th\u01b0\u1eddng k\u00e8m kho\u1ea3ng \u0111\u1ec7m 5 \u0111\u1ebfn 10 phi\u00ean \u0111\u1ec3 tr\u00e1nh r\u00f2 r\u1ec9 th\u00f4ng tin (MacKinlay, 1997, Journal of Economic Literature). C\u1eeda s\u1ed5 qu\u00e1 ng\u1eafn cho tham s\u1ed1 nhi\u1ec5u; c\u1eeda s\u1ed5 qu\u00e1 d\u00e0i l\u1ea1i d\u00f9ng th\u00f4ng tin \u0111\u00e3 c\u0169 v\u1ec1 h\u1ed3 s\u01a1 r\u1ee7i ro c\u1ee7a doanh nghi\u1ec7p.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">C\u00f3 th\u1ec3 ch\u1ea1y Event Study cho c\u1ed5 phi\u1ebfu HNX ho\u1eb7c UPCoM kh\u00f4ng?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00f3, nh\u01b0ng ph\u1ea3i x\u1eed l\u00fd r\u00f5 v\u1ea5n \u0111\u1ec1 thanh kho\u1ea3n m\u1ecfng. Nhi\u1ec1u m\u00e3 HNX v\u00e0 UPCoM th\u01b0\u1eddng xuy\u00ean c\u00f3 phi\u00ean kh\u00f4ng kh\u1edbp l\u1ec7nh, l\u00e0m l\u1ec7ch \u01b0\u1edbc l\u01b0\u1ee3ng beta b\u1eb1ng b\u00ecnh ph\u01b0\u01a1ng nh\u1ecf nh\u1ea5t. C\u00e1c hi\u1ec7u ch\u1ec9nh nh\u01b0 \u01b0\u1edbc l\u01b0\u1ee3ng c\u1ee7a Scholes v\u00e0 Williams (1977) hay Dimson (1979), ho\u1eb7c d\u00f9ng m\u00f4 h\u00ecnh hi\u1ec7u ch\u1ec9nh theo th\u1ecb tr\u01b0\u1eddng, gi\u00fap m\u1ed9t Event Study tr\u00ean c\u00e1c m\u00e3 k\u00e9m thanh kho\u1ea3n c\u1ee7a Vi\u1ec7t Nam tr\u1edf n\u00ean v\u1eefng ch\u1eafc.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Bi\u00ean \u0111\u1ed9 dao \u0111\u1ed9ng c\u00f3 l\u00e0m l\u1ec7ch k\u1ebft qu\u1ea3 Event Study t\u1ea1i Vi\u1ec7t Nam kh\u00f4ng?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">C\u00f3 th\u1ec3. V\u00ec HOSE gi\u1edbi h\u1ea1n bi\u1ebfn \u0111\u1ed9ng ng\u00e0y \u1edf 7%, HNX \u1edf 10% v\u00e0 UPCoM \u1edf 15% (quy ch\u1ebf giao d\u1ecbch, t\u00ednh \u0111\u1ebfn th\u00e1ng 7\/2026), m\u1ed9t ph\u1ea3n \u1ee9ng m\u1ea1nh c\u00f3 th\u1ec3 b\u1ecb tr\u1ea3i qua nhi\u1ec1u phi\u00ean tr\u1ea7n ho\u1eb7c s\u00e0n li\u00ean ti\u1ebfp. C\u1eeda s\u1ed5 1 phi\u00ean khi \u0111\u00f3 \u0111\u00e1nh gi\u00e1 th\u1ea5p hi\u1ec7u \u1ee9ng th\u1eadt, n\u00ean ng\u01b0\u1eddi nghi\u00ean c\u1ee9u m\u1edf r\u1ed9ng c\u1eeda s\u1ed5 s\u1ef1 ki\u1ec7n v\u00e0 \u0111\u00e1nh d\u1ea5u c\u00e1c chu\u1ed7i phi\u00ean ch\u1ea1m bi\u00ean \u0111\u1ed9.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">C\u1ea7n nh\u1eefng d\u1eef li\u1ec7u g\u00ec \u0111\u1ec3 x\u00e2y d\u1ef1ng Event Study cho Vi\u1ec7t Nam?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">T\u1ed1i thi\u1ec3u g\u1ed3m: gi\u00e1 ng\u00e0y k\u00e8m h\u1ec7 s\u1ed1 \u0111i\u1ec1u ch\u1ec9nh theo nghi\u1ec7p v\u1ee5 doanh nghi\u1ec7p, gi\u00e1 tham chi\u1ebfu, kh\u1ed1i l\u01b0\u1ee3ng kh\u1edbp l\u1ec7nh v\u00e0 th\u1ecfa thu\u1eadn ghi t\u00e1ch ri\u00eang, chu\u1ed7i ch\u1ec9 s\u1ed1 th\u1ecb tr\u01b0\u1eddng, l\u1ecbch giao d\u1ecbch, v\u00e0 v\u1edbi c\u00e1c b\u00e0i to\u00e1n d\u00f2ng v\u1ed1n ngo\u1ea1i l\u00e0 d\u1eef li\u1ec7u mua b\u00e1n r\u00f2ng c\u1ee7a kh\u1ed1i ngo\u1ea1i c\u00f9ng room s\u1edf h\u1eefu c\u00f2n l\u1ea1i. B\u1ed9 d\u1eef li\u1ec7u Historical Price c\u1ee7a DataCore c\u00f3 \u0111\u1ee7 c\u00e1c tr\u01b0\u1eddng n\u00e0y cho HOSE, HNX v\u00e0 UPCoM.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"sources\">Ngu\u1ed3n tham kh\u1ea3o<\/h2>\n\n\n\n<ul class=\"wp-block-list\"><li><a href=\"https:\/\/www.jstor.org\/stable\/2525569\" target=\"_blank\" rel=\"noopener\">Fama, Fisher, Jensen v\u00e0 Roll, \"The Adjustment of Stock Prices to New Information\", International Economic Review, 1969<\/a><\/li><li><a href=\"https:\/\/www.jstor.org\/stable\/2729691\" target=\"_blank\" rel=\"noopener\">MacKinlay, \"Event Studies in Economics and Finance\", Journal of Economic Literature, th\u00e1ng 3\/1997<\/a><\/li><li><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/abs\/pii\/0304405X85900424\" target=\"_blank\" rel=\"noopener\">Brown v\u00e0 Warner, \"Using Daily Stock Returns: The Case of Event Studies\", Journal of Financial Economics, 1985<\/a><\/li><li><a href=\"https:\/\/www.sciencedirect.com\/science\/article\/abs\/pii\/0304405X77900411\" target=\"_blank\" rel=\"noopener\">Scholes v\u00e0 Williams, \"Estimating Betas from Nonsynchronous Data\", Journal of Financial Economics, 1977<\/a><\/li><li><a href=\"https:\/\/www.hsx.vn\/\" target=\"_blank\" rel=\"noopener\">S\u1edf Giao d\u1ecbch Ch\u1ee9ng kho\u00e1n Th\u00e0nh ph\u1ed1 H\u1ed3 Ch\u00ed Minh (HOSE), quy ch\u1ebf giao d\u1ecbch, truy c\u1eadp th\u00e1ng 7\/2026<\/a><\/li><li><a href=\"https:\/\/hnx.vn\/\" target=\"_blank\" rel=\"noopener\">S\u1edf Giao d\u1ecbch Ch\u1ee9ng kho\u00e1n H\u00e0 N\u1ed9i (HNX), quy ch\u1ebf giao d\u1ecbch, truy c\u1eadp th\u00e1ng 7\/2026<\/a><\/li><li><a href=\"https:\/\/vietnamnews.vn\/economy\/1254864\/investors-to-be-able-to-trade-stocks-on-t-2-settlement-cycle.html\" target=\"_blank\" rel=\"noopener\">Vietnam News, \"Investors to be able to trade stocks on T+2 settlement cycle\", 25\/8\/2022<\/a><\/li><li><a href=\"https:\/\/vsd.vn\/en\" target=\"_blank\" rel=\"noopener\">T\u1ed5ng c\u00f4ng ty L\u01b0u k\u00fd v\u00e0 B\u00f9 tr\u1eeb Ch\u1ee9ng kho\u00e1n Vi\u1ec7t Nam (VSDC), th\u00f4ng b\u00e1o thanh to\u00e1n, 2022<\/a><\/li><\/ul>","protected":false},"excerpt":{"rendered":"<p>TL;DR: Event Study l\u00e0 ph\u01b0\u01a1ng ph\u00e1p \u0111\u1ecbnh l\u01b0\u1ee3ng \u0111o l\u01b0\u1eddng vi\u1ec7c m\u1ed9t s\u1ef1 ki\u1ec7n c\u1ee5 th\u1ec3, ch\u1eb3ng h\u1ea1n c\u00f4ng b\u1ed1 c\u1ed5 t\u1ee9c hay \u0111\u01b0\u1ee3c th\u00eam v\u00e0o r\u1ed5 ch\u1ec9 s\u1ed1, c\u00f3 t\u1ea1o ra l\u1ee3i su\u1ea5t b\u1ea5t th\u01b0\u1eddng cho c\u1ed5 phi\u1ebfu hay kh\u00f4ng. B\u00e0i \u0111\u1ea7u ti\u00ean trong series nghi\u00ean c\u1ee9u c\u1ee7a DataCore gi\u1ea3i th\u00edch v\u00ec sao m\u1ed9t [&hellip;]<\/p>\n","protected":false},"author":13,"featured_media":2698,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"content-type":"","_uag_custom_page_level_css":"","_swt_meta_header_display":false,"_swt_meta_footer_display":false,"_swt_meta_site_title_display":false,"_swt_meta_sticky_header":false,"_swt_meta_transparent_header":false,"footnotes":""},"categories":[19,1771],"tags":[1932,1935,1938,1807,1907],"class_list":["post-2615","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog-vi","category-finance-vi","tag-chung-khoan-viet-nam-vi-vi","tag-du-lieu-thi-truong-vi-vi","tag-event-study-vi-vi","tag-vn-index-vi","tag-w30-2026-vi-vi"],"uagb_featured_image_src":{"full":["https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/hose-stock-exchange-hcmc.jpg",1280,720,false],"thumbnail":["https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/hose-stock-exchange-hcmc-150x150.jpg",150,150,true],"medium":["https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/hose-stock-exchange-hcmc-300x169.jpg",300,169,true],"medium_large":["https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/hose-stock-exchange-hcmc-768x432.jpg",768,432,true],"large":["https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/hose-stock-exchange-hcmc-1024x576.jpg",1024,576,true],"1536x1536":["https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/hose-stock-exchange-hcmc.jpg",1280,720,false],"2048x2048":["https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/hose-stock-exchange-hcmc.jpg",1280,720,false],"trp-custom-language-flag":["https:\/\/blog.datacore.vn\/wp-content\/uploads\/2026\/07\/hose-stock-exchange-hcmc-18x10.jpg",18,10,true]},"uagb_author_info":{"display_name":"Bui Huong","author_link":"https:\/\/blog.datacore.vn\/vi\/author\/huongbui\/"},"uagb_comment_info":0,"uagb_excerpt":"TL;DR: Event Study l\u00e0 ph\u01b0\u01a1ng ph\u00e1p \u0111\u1ecbnh l\u01b0\u1ee3ng \u0111o l\u01b0\u1eddng vi\u1ec7c m\u1ed9t s\u1ef1 ki\u1ec7n c\u1ee5 th\u1ec3, ch\u1eb3ng h\u1ea1n c\u00f4ng b\u1ed1 c\u1ed5 t\u1ee9c hay \u0111\u01b0\u1ee3c th\u00eam v\u00e0o r\u1ed5 ch\u1ec9 s\u1ed1, c\u00f3 t\u1ea1o ra l\u1ee3i su\u1ea5t b\u1ea5t th\u01b0\u1eddng cho c\u1ed5 phi\u1ebfu hay kh\u00f4ng. B\u00e0i \u0111\u1ea7u ti\u00ean trong series nghi\u00ean c\u1ee9u c\u1ee7a DataCore gi\u1ea3i th\u00edch v\u00ec sao m\u1ed9t&hellip;","_links":{"self":[{"href":"https:\/\/blog.datacore.vn\/vi\/wp-json\/wp\/v2\/posts\/2615","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.datacore.vn\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.datacore.vn\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.datacore.vn\/vi\/wp-json\/wp\/v2\/users\/13"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.datacore.vn\/vi\/wp-json\/wp\/v2\/comments?post=2615"}],"version-history":[{"count":6,"href":"https:\/\/blog.datacore.vn\/vi\/wp-json\/wp\/v2\/posts\/2615\/revisions"}],"predecessor-version":[{"id":2708,"href":"https:\/\/blog.datacore.vn\/vi\/wp-json\/wp\/v2\/posts\/2615\/revisions\/2708"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.datacore.vn\/vi\/wp-json\/wp\/v2\/media\/2698"}],"wp:attachment":[{"href":"https:\/\/blog.datacore.vn\/vi\/wp-json\/wp\/v2\/media?parent=2615"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.datacore.vn\/vi\/wp-json\/wp\/v2\/categories?post=2615"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.datacore.vn\/vi\/wp-json\/wp\/v2\/tags?post=2615"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}