SPY three-down-days overnight bounce
After three straight down closes in SPY, buy at the close and sell at the next morning's open.
What they did
QuantifiedStrategies backtested a simple mean-reversion rule in SPY from 1993 in Amibroker: SPY down three days in a row (close to close), enter on the close of the third down day, exit at the next day's open.
How it went
QuantifiedStrategies' claims: they show only an equity curve image, with no performance numbers in the post text. We don't restate any figures.
Sources:
Worth knowing
- You must be able to buy right at the close. Market-on-close orders or the last minutes of the session matter.
- Overnight gaps cut both ways, and one bad gap can erase many small wins.
- Results are only in a chart image. Run your own backtest before paper trading.
The prompt
Each trading day at [3:50 PM ET], check SPY's daily closes.
Entry: if SPY is on track to close lower for the [3]rd consecutive day (today's price below yesterday's close, and the two prior days were also down) and I'm flat, propose a market-on-close (or last-minute limit) buy of $[amount] SPY.
Exit: propose selling at the next day's open (market-on-open or a limit within [0.1]% of the open).
Log the entry price, exit price and overnight gap for every trade.
SAFETY DEFAULTS (keep unless you deliberately change them):
- Use the PAPER trading account only. Never touch a live account.
- Before every order, show me: symbol, side, size, order type, limit price, stop, and the rule that triggered it. Then WAIT for my "approve".
- Hard limits: max [$500] per trade, max [3] open positions, stop all trading for the day after a loss of [$300].
- Log every signal, decision and fill to [a running log / spreadsheet] with timestamps.To go fully autonomous: (1) run on paper for at least [4–8 weeks] or [30+ trades]; (2) delete the 'WAIT for my approve' line and keep the hard limits; (3) switch to live keys or account. On Robinhood, turn off trade approvals in your agent settings, but note that some orders can still require in-app approval or acknowledging a pre-trade alert, so unattended execution isn't guaranteed for every order. IBKR's AI connector always asks for approval; use its regular API for unattended trading. Never remove the daily loss limit.