BeatDrift

BeatDrift is a research project. It follows one simple, published rule about company earnings and tracks how it performs in a paper (simulated) portfolio, so you can watch the results build up week by week. THE IDEA When a large US company reports earnings well above what analysts expected, its share price often keeps drifting the same way for weeks afterwards. Researchers call this post-earnings-announcement drift. BeatDrift tests whether it still holds in the largest companies, live and in the open. THE RULE A company counts as a signal when all four of these are true at the close of the reaction day: • Size: worth $200B or more, or $50–200B (an experimental tier) • Beat: earnings beat the estimate by 5–100% (35–100% for the mid tier) • Trend: the daily MACD is above zero • Outlook: next quarter's estimate is above the result just reported The paper portfolio "buys" at the next open and "sells" before the company's next report. WHAT'S IN THE APP • Portfolio: the paper account, its value, its returns against SPY and its holdings. Set your own paper size and currency. • Tech focus: the same rule applied to technology companies only, tracked side by side. • Trades: every open and closed paper trade, with the exit timeline. • Results: this week's earnings reports from $50B+ US companies, in your local time. Tap any result to see which of the four checks it passed. • Strategy: the backtest from 2006 to 2026, year by year, including the years it lagged. • Notifications (optional): when the strategy signals, and when the paper portfolio buys or sells. RESEARCH, NOT ADVICE BeatDrift is for study and education only. Every portfolio in the app is simulated, and no real money is involved. Nothing in the app is financial advice or a recommendation to buy or sell any investment. Backtested and paper results are hypothetical, past performance is not a reliable guide to future results, and investing can lose money. Do not use this app to trade a real account. The full research note, including what didn't work and the study's limits, is at beatdrift.org.