Quality strategy
Post-Earnings-Announcement Drift
Buy positive earnings surprises that tend to keep drifting upward for weeks — the market underreacts to a genuine beat, and the price takes time to catch up.
~4–13 weeks per positionIntermediate
Ray Ball & Philip Brown — “An Empirical Evaluation of Accounting Income Numbers”, Journal of Accounting Research (1968); characterised as a distinct anomaly by Bernard & Thomas (1989–90)