Is Post-Earnings Drift Still Tradable? 43,000 Announcements, 2023–2026

For fifty years, stocks kept drifting after earnings surprises; recent research says the effect is mostly gone. On 43,111 US announcements (2023–2026), the best surprises still beat the worst by 1.7 points over 60 trading days, including large caps (2.0 points), but the edge fell from 2.6 points in 2023–24 to 0.5 in 2025–26. A mid- and large-cap long-short book earned 6.0% a year after 10 bp costs and 2.1% at 30 bp. Plus how I would put it to an investment committee. New to earnings drift? The first two minutes are a plain-English primer. Full article: https://www.guptagaurav.info/articles/earn... Code: https://github.com/guptagaurav-info/earnin... Research note (PDF): on the article page Narration uses an AI voice model of my own voice; the intro and close are recorded on camera. The research, code and script were produced with AI assistance and reviewed by me. Sources are credited in the article. Independent research on public data; not deployed; not investment advice. Dollar figures are illustrative.