$PYPL +4.64% on 1.5× volume

After days like this

Matching days: +3.1% to +7.0% day, on ≥1.3x avg volume, below the 50-day · large caps. How often the stock closed higher afterwards, vs. a typical day (since 2016).

Next day: closed higher less often than after a typical day.

The rule, backtested

Buy at the next open after a matching day, hold 1 day, sell at the open. Run on 58 large caps with slippage, compared with buying any day the same way. The out-of-sample period is the most recent 30% of the data.

Backtest (buy next open, hold 1 day, net of slippage): -0.45%/trade vs -0.01% buying any day (579 trades since 2016); out-of-sample 2023-2026: -0.35%.

Run this setup yourself

This is the complete AlgoDeploy config behind the backtest above. Change symbol to test the same setup on any ticker, or adjust the thresholds and holding period.

# AlgoDeploy setup rule for PYPL, from its 2026-09-25 move.
# Run:  algodeploy backtest setup_rule.yaml
# Change `symbol` to test the same setup on any ticker.
name: "Setup: +3.1% to +7.0% day, on ≥1.3x avg volume, below the 50-day, hold 1d"
symbol: "PYPL"
start: "2016-09-28"
end: "2026-09-26"
equity: 100000
data:
  provider: "yfinance"
entry:
  conditions:
    - "pct_change(1) >= 0.031"
    - "pct_change(1) <= 0.07"
    - "volume_ratio(20) >= 1.3"
    - "close < sma(50)"
  position_size: "95%"
exit:
  max_hold_days: 1
fill_on: "next_open"
slippage_bps: 5
commission_per_share: 0.005