Opening range breakout strategy for US stocks

An opening range breakout strategy for US stocks. The first minutes of the session set a high and a low; entering on a clean break of that high with above-normal turnover avoids most of the fake-outs that make breakout trading frustrating.

1. The rule

# BUY — break of the opening range, with turnover confirmation if HhmmSs >= 93500 and Price > HighestPrice(300) and TradeAmount > AvgTradeAmount(300) * 3: Buy()# SELL if ProfitPct >= 1.5 or ProfitPct <= -0.7 or HoldTime >= 900: Sell()

2. Why these conditions

The turnover multiple is compared against the symbol's own recent average rather than a fixed dollar figure. An absolute threshold passes constantly on a heavily traded name and never on a thin one, which is the opposite of what a surge filter is for.

3. When it fails

It fails on gap-and-fade mornings. Price clears the high, the buyers were the gap chasers, and the move reverses inside a minute. The time exit is what saves you there, not the stop. It also fails in a quiet market where the high being broken is three cents above the average price. Nothing in these conditions measures how far the move has already travelled, so a three-cent break and a fifty-cent break look identical to the code.

4. What the round trip asks of it

The 1.5% target against a 0.7% stop looks like it only needs to be right a third of the time. It does — if trading were free. We measured what a $5,000 market order actually pays on these names: about 38 basis points one way, roughly 0.75% round trip (what day trading a US stock really costs). Put that in and the break-even win rate goes from 32% to 66%. That is not an argument against the strategy. It is an argument for taking the opening range seriously as a selection problem: the break has to be big enough that 0.75% is a small share of it. It is also why the opening half hour, despite the wide spreads, is still the window where the typical minute covers its own cost — see the opening 30 minutes is the easiest day trading window.

5. What to change first

Try the lookback window before anything else. HighestPrice(300) is five minutes of history; at 900 it becomes a much rarer, larger breakout — and a larger break is exactly what makes the cost above tolerable. Change one number, keep the rest, and compare trade count as well as result. A filter that improves the average by cutting you to four trades has not taught you anything. Run it on your own recordings first: how to backtest a day trading strategy on US stocks. Every factor used here is defined in the day trading indicators and factors reference.