{"id":23771,"date":"2023-12-06T08:53:12","date_gmt":"2023-12-06T08:53:12","guid":{"rendered":"https:\/\/masterskills.org\/blog\/dinh-kien-tien-lieu-look-ahead-bias-la-gi-dac-diem.html"},"modified":"2023-12-22T09:04:28","modified_gmt":"2023-12-22T02:04:28","slug":"dinh-kien-tien-lieu-look-ahead-bias-la-gi-dac-diem","status":"publish","type":"post","link":"https:\/\/masterskills.org\/blog\/dinh-kien-tien-lieu-look-ahead-bias-la-gi-dac-diem.html","title":{"rendered":"\u0110\u1ecbnh ki\u1ebfn ti\u00ean li\u1ec7u (Look-Ahead Bias) l\u00e0 g\u00ec? \u0110\u1eb7c \u0111i\u1ec3m"},"content":{"rendered":"
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(\u1ea2nh minh h\u1ecda: Medium)<\/p>\n<\/figcaption><\/figure>\n

\u0110\u1ecbnh ki\u1ebfn ti\u00ean li\u1ec7u<\/font><\/h2>\n

Kh\u00e1i ni\u1ec7m<\/b><\/p>\n

\u0110\u1ecbnh ki\u1ebfn ti\u00ean li\u1ec7u\u00a0<\/b>trong ti\u1ebfng Anh l\u00e0 Look-Ahead Bias.<\/b><\/p>\n

\u0110\u1ecbnh ki\u1ebfn ti\u00ean li\u1ec7u<\/b> x\u1ea3y ra khi s\u1eed d\u1ee5ng th\u00f4ng tin ho\u1eb7c d\u1eef li\u1ec7u c\u1ee7a m\u1ed9t nghi\u00ean c\u1ee9u ho\u1eb7c m\u00f4 h\u00ecnh kh\u00f4ng \u0111\u01b0\u1ee3c bi\u1ebft \u0111\u1ebfn ho\u1eb7c kh\u00f4ng c\u00f3 s\u1eb5n trong qu\u00e1 tr\u00ecnh ph\u00e2n t\u00edch, d\u1eabn \u0111\u1ebfn k\u1ebft qu\u1ea3 c\u1ee7a nghi\u00ean c\u1ee9u ho\u1eb7c m\u00f4 h\u00ecnh kh\u00f4ng ch\u00ednh x\u00e1c.<\/p>\n

Quan tr\u1ecdng h\u01a1n, \u0111\u1ecbnh ki\u1ebfn ti\u00ean li\u1ec7u c\u00f3 th\u1ec3 v\u00f4 t\u00ecnh l\u00e0m cho k\u1ebft qu\u1ea3 c\u1ee7a m\u00f4 h\u00ecnh g\u1ea7n v\u1edbi k\u1ebft qu\u1ea3 mong mu\u1ed1n c\u1ee7a vi\u1ec7c \u0111\u00e1nh gi\u00e1.\u00a0<\/p>\n

\u0110\u1ecbnh ki\u1ebfn n\u00e0y l\u00e0m c\u00e1c nh\u00e0 kinh t\u1ebf v\u00e0 nh\u00e0 ph\u00e2n t\u00edch \u0111\u1eb7t qu\u00e1 nhi\u1ec1u ni\u1ec1m tin v\u00e0o m\u00f4 h\u00ecnh c\u1ee7a m\u00ecnh, v\u1ec1 kh\u1ea3 n\u0103ng m\u00f4 h\u00ecnh c\u00f3 th\u1ec3 d\u1ef1 \u0111o\u00e1n, v\u00e0 gi\u1ea3m thi\u1ec3u c\u00e1c kh\u1ea3 n\u0103ng x\u1ea3y ra trong t\u01b0\u01a1ng lai.<\/p>\n

C\u00e1c nh\u00e0 \u0111\u1ea7u t\u01b0 c\u0169ng c\u1ea7n nh\u1eadn th\u1ee9c \u0111\u01b0\u1ee3c kh\u1ea3 n\u0103ng x\u1ea3y ra c\u1ee7a \u0111\u1ecbnh ki\u1ebfn ti\u00ean li\u1ec7u khi \u0111\u00e1nh gi\u00e1 c\u00e1c chi\u1ebfn l\u01b0\u1ee3c giao d\u1ecbch c\u1ee5 th\u1ec3 s\u1eed d\u1ee5ng d\u1eef li\u1ec7u trong qu\u00e1 kh\u1ee9.<\/p>\n

\u0110\u1eb7c \u0111i\u1ec3m c\u1ee7a \u0110\u1ecbnh ki\u1ebfn ti\u00ean li\u1ec7u<\/font><\/h3>\n

\u0110\u1ecbnh ki\u1ebfn ti\u00ean li\u1ec7u\u00a0<\/b>th\u01b0\u1eddng x\u1ea3y ra trong c\u00e1c k\u1ecbch b\u1ea3n “c\u00f3 th\u1ec3 x\u1ea3y ra”, trong \u0111\u00f3 m\u1ed9t nh\u00e0 \u0111\u1ea7u t\u01b0 ho\u1eb7c c\u00e1c chuy\u00ean gia s\u1ebd c\u00e2n nh\u1eafc xem c\u00f3 c\u01a1 h\u1ed9i n\u00e0o \u0111\u00e3 b\u1ecf l\u1ee1 v\u00ec\u00a0nh\u1eadn th\u1ee9c mu\u1ed9n\u00a0hay kh\u00f4ng.<\/p>\n

\u0110i\u1ec1u m\u00e0 m\u1ed9t ng\u01b0\u1eddi kh\u00f4ng nh\u1eadn ra l\u00e0 hi\u1ec7n t\u1ea1i h\u1ecd bi\u1ebft nhi\u1ec1u h\u01a1n khi nh\u00ecn l\u1ea1i qu\u00e1 kh\u1ee9, h\u01a1n l\u00e0 so v\u1edbi l\u00fac h\u1ecd \u0111\u01b0a ra quy\u1ebft \u0111\u1ecbnh.<\/p>\n

Do \u0111\u00f3, c\u00f3 th\u1ec3 kh\u00f4ng \u0111\u00fang \u0111\u1eafn khi qu\u00e1 ch\u00fa tr\u1ecdng \u0111\u00e1nh gi\u00e1 hi\u1ec7u su\u1ea5t \u0111\u1ea7u t\u01b0 c\u1ee7a m\u1ed9t ng\u01b0\u1eddi trong qu\u00e1 kh\u1ee9, \u0111\u1eb7c bi\u1ec7t l\u00e0 khi thi\u1ebfu nh\u1eefng th\u00f4ng tin quan tr\u1ecdng.<\/p>\n

N\u1ebfu m\u1ed9t nh\u00e0 \u0111\u1ea7u t\u01b0 \u0111ang ki\u1ec3m tra hi\u1ec7u su\u1ea5t c\u1ee7a chi\u1ebfn l\u01b0\u1ee3c giao d\u1ecbch, h\u1ecd n\u00ean ch\u1ec9 s\u1eed d\u1ee5ng th\u00f4ng tin c\u00f3 s\u1eb5n t\u1ea1i th\u1eddi \u0111i\u1ec3m giao d\u1ecbch \u0111\u1ec3 tr\u00e1nh s\u1ef1\u00a0\u0111\u1ecbnh ki\u1ebfn ti\u00ean li\u1ec7u.<\/i><\/p>\n

V\u00ed d\u1ee5, n\u1ebfu m\u1ed9t giao d\u1ecbch \u0111\u01b0\u1ee3c m\u00f4 ph\u1ecfng d\u1ef1a tr\u00ean th\u00f4ng tin kh\u00f4ng c\u00f3 s\u1eb5n t\u1ea1i th\u1eddi \u0111i\u1ec3m giao d\u1ecbch, ch\u1eb3ng h\u1ea1n nh\u01b0 con s\u1ed1 thu \u0111\u01b0\u1ee3c h\u00e0ng qu\u00ed \u0111\u01b0\u1ee3c c\u00f4ng b\u1ed1 sau \u0111\u00f3 m\u1ed9t th\u00e1ng, th\u00ec n\u00f3 s\u1ebd l\u00e0m gi\u1ea3m t\u00ednh ch\u00ednh x\u00e1c c\u1ee7a hi\u1ec7u su\u1ea5t th\u1ef1c s\u1ef1 c\u1ee7a chi\u1ebfn l\u01b0\u1ee3c giao d\u1ecbch, v\u00e0 c\u00f3 kh\u1ea3 n\u0103ng l\u00e0m sai l\u1ec7ch k\u1ebft qu\u1ea3 c\u00f3 l\u1ee3i cho k\u1ebft qu\u1ea3 mong mu\u1ed1n.<\/p>\n

\u0110\u1ecbnh ki\u1ebfn ti\u00ean li\u1ec7u v\u00e0 c\u00e1c \u0111\u1ecbnh ki\u1ebfn kh\u00e1c trong \u0111\u1ea7u t\u01b0<\/font><\/h3>\n

\u0110\u1ecbnh ki\u1ebfn ti\u00ean li\u1ec7u\u00a0<\/b>l\u00e0 m\u1ed9t trong nhi\u1ec1u \u0111\u1ecbnh ki\u1ebfn ph\u1ea3i \u0111\u01b0\u1ee3c t\u00ednh t\u1edbi khi ch\u1ea1y m\u00f4 h\u00ecnh.<\/p>\n

C\u00e1c\u00a0\u0111\u1ecbnh ki\u1ebfn\u00a0ph\u1ed5 bi\u1ebfn kh\u00e1c l\u00e0\u00a0thi\u00ean l\u1ec7ch trong ch\u1ecdn m\u1eabu, \u0111\u1ecbnh ki\u1ebfn th\u1eddi gian v\u00e0 thi\u00ean l\u1ec7ch s\u1ed1ng s\u00f3t.<\/p>\n

T\u1ea5t c\u1ea3 c\u00e1c \u0111\u1ecbnh ki\u1ebfn\u00a0n\u00e0y c\u00f3 kh\u1ea3 n\u0103ng l\u00e0m cho k\u1ebft qu\u1ea3 c\u1ee7a m\u00f4 h\u00ecnh g\u1ea7n v\u1edbi k\u1ebft qu\u1ea3 mong mu\u1ed1n h\u01a1n, v\u00ec c\u00e1c tham s\u1ed1 \u0111\u1ea7u v\u00e0o c\u1ee7a m\u00f4 h\u00ecnh c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c ch\u1ecdn theo c\u00e1ch c\u00f3 l\u1ee3i cho k\u1ebft qu\u1ea3 mong mu\u1ed1n.<\/p>\n

Nh\u1eefng \u0111\u1ecbnh ki\u1ebfn n\u00e0y \u0111\u01b0\u1ee3c th\u1ea5y r\u00f5 nh\u1ea5t khi c\u00e1c nh\u00e0 \u0111\u1ea7u t\u01b0 nh\u00ecn l\u1ea1i c\u1ed5 phi\u1ebfu trong m\u1ed9t n\u0103m.<\/p>\n

C\u00e1c c\u1ed5 phi\u1ebfu \u0111\u00e3 ho\u1ea1t \u0111\u1ed9ng t\u1ed1t trong su\u1ed1t c\u1ea3 n\u0103m c\u00f3 th\u1ec3 b\u1ecb mua qu\u00e1 m\u1ee9c do nh\u00e0 \u0111\u1ea7u t\u01b0 gi\u1ea3 \u0111\u1ecbnh r\u1eb1ng c\u1ed5 phi\u1ebfu c\u0169ng s\u1ebd l\u00e0m \u0111i\u1ec1u t\u01b0\u01a1ng t\u1ef1 v\u00e0o n\u0103m sau.<\/p>\n

M\u1eb7c d\u00f9 hi\u1ec7u su\u1ea5t trong qu\u00e1 kh\u1ee9 \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn hi\u1ec7u su\u1ea5t trong t\u01b0\u01a1ng lai, nh\u01b0ng \u0111i\u1ec1u quan tr\u1ecdng \u0111\u1ed1i v\u1edbi c\u00e1c nh\u00e0 \u0111\u1ea7u t\u01b0 l\u00e0 xem x\u00e9t ph\u00e2n t\u00edch c\u00e1c y\u1ebfu t\u1ed1 c\u01a1 b\u1ea3n c\u1ee7a c\u00f4ng ty m\u1ed9t c\u00e1ch c\u1ea9n th\u1eadn, v\u00ec lu\u00f4n c\u00f3 nguy c\u01a1 c\u00f4ng ty b\u1ecb \u0111\u1ecbnh gi\u00e1 qu\u00e1 cao.<\/p>\n

N\u1ebfu l\u1ea5y c\u00e1c c\u1ed5 phi\u1ebfu c\u00f3 hi\u1ec7u su\u1ea5t r\u1ea5t t\u1ed1t v\u00e0o cu\u1ed1i n\u0103m v\u00e0 sau \u0111\u00f3 c\u1ed1 g\u1eafng ch\u1ecdn c\u00e1c \u0111i\u1ec3m d\u1eef li\u1ec7u ph\u1ed5 bi\u1ebfn c\u00f3 \u0111\u01b0\u1ee3c v\u00e0o \u0111\u1ea7u n\u0103m, ch\u1eb3ng h\u1ea1n nh\u01b0 ph\u1ea1m vi ch\u1ec9 s\u1ed1 P\/E, th\u00ec nh\u00e0 \u0111\u1ea7u t\u01b0 d\u1ec5 b\u1ecb \u0111\u1ecbnh ki\u1ebfn ti\u00ean li\u1ec7u.<\/p>\n

L\u00ed do l\u00e0 v\u00ec nh\u00e0 \u0111\u1ea7u t\u01b0 ch\u1ec9 nh\u00ecn v\u00e0o c\u00e1c c\u1ed5 phi\u1ebfu m\u00e0 h\u1ecd bi\u1ebft, v\u1edbi m\u1ee9c t\u0103ng tr\u01b0\u1edfng cao, thay v\u00ec ph\u1ea3i nh\u00ecn nh\u1eadn t\u1ea5t c\u1ea3 c\u00e1c c\u1ed5 phi\u1ebfu c\u00f3 ph\u1ea1m vi ch\u1ec9 s\u1ed1 P\/E t\u01b0\u01a1ng t\u1ef1 t\u1ea1i th\u1eddi \u0111i\u1ec3m \u0111\u00f3.<\/p>\n

Khi kh\u00f4ng nh\u00ecn nh\u1eadn \u0111\u1ea7y \u0111\u1ee7 c\u00e1c lo\u1ea1i c\u1ed5 phi\u1ebfu, nh\u00e0 \u0111\u1ea7u t\u01b0 s\u1ebd b\u1ecb t\u1ef1 tin th\u00e1i qu\u00e1 v\u1ec1 ch\u1ec9 s\u1ed1 P\/E nh\u01b0 l\u00e0 th\u01b0\u1edbc \u0111o ch\u00ednh \u0111\u1ec3 d\u1ef1 \u0111o\u00e1n v\u1ec1 t\u01b0\u01a1ng lai.<\/p>\n

\u0110\u1ecbnh ki\u1ebfn ti\u00ean li\u1ec7u c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c s\u1eeda ch\u1eefa b\u1eb1ng c\u00e1ch m\u1edf r\u1ed9ng m\u1eabu cho t\u1ea5t c\u1ea3 c\u00e1c c\u1ed5 phi\u1ebfu ph\u00f9 h\u1ee3p v\u1edbi ti\u00eau ch\u00ed c\u1ee5 th\u1ec3 c\u1ee7a nh\u00e0 \u0111\u1ea7u t\u01b0 v\u00e0o \u0111\u1ea7u n\u0103m v\u00e0 nh\u00e0 \u0111\u1ea7u t\u01b0 c\u0169ng n\u00ean theo d\u00f5i k\u0129 k\u1ebft qu\u1ea3.<\/p>\n

(Theo Investopedia)<\/i><\/p>\n<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"

\n \u0110\u1ecbnh ki\u1ebfn ti\u00ean li\u1ec7u (ti\u1ebfng Anh: Look-Ahead Bias) x\u1ea3y ra khi s\u1eed d\u1ee5ng th\u00f4ng tin ho\u1eb7c d\u1eef li\u1ec7u c\u1ee7a m\u1ed9t nghi\u00ean c\u1ee9u ho\u1eb7c m\u00f4 h\u00ecnh kh\u00f4ng \u0111\u01b0\u1ee3c bi\u1ebft \u0111\u1ebfn ho\u1eb7c kh\u00f4ng c\u00f3 s\u1eb5n trong qu\u00e1 tr\u00ecnh ph\u00e2n t\u00edch, d\u1eabn \u0111\u1ebfn k\u1ebft qu\u1ea3 nghi\u00ean c\u1ee9u ho\u1eb7c m\u00f4 h\u00ecnh kh\u00f4ng ch\u00ednh x\u00e1c.\n <\/div>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[414],"tags":[],"_links":{"self":[{"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/posts\/23771"}],"collection":[{"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/comments?post=23771"}],"version-history":[{"count":0,"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/posts\/23771\/revisions"}],"wp:attachment":[{"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/media?parent=23771"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/categories?post=23771"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/tags?post=23771"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}