Analyst Revision Momentum
Mechanism. Analyst rating and target changes are released in clusters and diffuse slowly: institutions act on
them over days and weeks, and further revisions tend to follow the first (Womack 1996; Jegadeesh, Kim, Krische &
Lee 2004). Upgrades released after the close are priced at the open.
Hypothesis. Stocks with the strongest net upgrade flow and rising price targets over the trailing 20
sessions outperform overnight; net downgrades underperform.
Signature feature. Net upgrade count over the trailing 20 sessions (upgrades minus downgrades from grades,
counting only actions labeled upgrade/downgrade), divided by the number of distinct grading firms that covered the
name in the last year. Secondary: change in the average price target (last month vs last quarter from
price-target-summary) relative to price.
Data. grades?symbol= (full history, per symbol; fan out over the universe and publish as a shared dataset),
grades-latest-news and price-target-latest-news (feeds, cheap), price-target-summary?symbol=.
Implementation sketch. Publish a shared grades table for the universe; compute net upgrades in the last 20
sessions and the price-target drift; score = rank-average, sector-neutral. Refresh the per-symbol table weekly and
use the feeds daily.
Falsification. Top-decile sector-neutral overnight excess not positive after 40 days.