London Breakout Strategy: An Example Rule Set, Sizing and How to Test It

The London breakout strategy marks the high and low of the quiet Asian session, then trades the first break of that range after London opens. The idea is that European volume often pushes price out of the overnight range, and some of those moves carry on. Below is a complete example rule set with entry, stop and target, plus a worked trade. It then covers when the setup fails and how to size and test it for a prop firm account. Treat the rules as a starting point to test, not a proven edge.

What is the London breakout?

During the Tokyo session, EURUSD and GBPUSD often trade in a tight range because European and US dealers are mostly away. When London opens at about 8am London time, volume rises sharply. Orders that built up overnight get filled, and price often leaves the Asian range in one direction.

The breakout trader does not predict the direction. They place orders on both sides and let the market choose. The risk is that the first break is a false one, where price pokes out, triggers orders, and reverses. Every rule below exists to manage that risk.

An example London breakout rule set

These are example rules. The thresholds are starting points for testing, not settings with a known result.

1. Pair: GBPUSD or EURUSD, one at a time.
2. Range: mark the high and low from midnight to 7am London time on a 15 minute chart.
3. Filter: skip the day if the range is wider than half of the 14 day ATR, or narrower than a fifth of it. Skip days with high impact UK, euro area or US releases before noon London time.
4. Entry: at 7am London time, place a buy stop 2 pips above the range high and a sell stop 2 pips below the range low. When one fills, cancel the other.
5. Stop: at the midpoint of the Asian range.
6. Target: 1.5 times the distance from entry to stop.
7. Time exits: cancel unfilled orders at 10am London time. Close any open trade at noon London time, before US data at 8:30am New York.
8. Limit: one trade per day. No second entry after a loss.

Timing the range in London time keeps it stable through daylight saving changes. The noon exit stops the trade from running into US data, which can reverse a London move in seconds.

Worked example: a GBPUSD long

Example figures. The Asian range on GBPUSD runs from 1.27100 to 1.27400, which is 30 pips. The 14 day ATR is 90 pips, so the range sits between the filter limits of 18 and 45 pips. There is no major news before noon.

• Buy stop at 1.27420. Sell stop at 1.27080.
• Midpoint, and stop for either side, at 1.27250.
• Long risk: 1.27420 minus 1.27250 is 17 pips. Target is 1.5 × 17 = 25.5 pips, at 1.27675.

At 8:20am London time, GBPUSD trades through 1.27420 and the long fills. The sell stop is cancelled. Risk per trade is $300, so size is $300 ÷ (17 × $10) = 1.76 lots. If the target fills, the gain is 25.5 × $10 × 1.76 = $448.80. If the stop fills, the loss is 17 × $10 × 1.76 = $299.20.

Now add costs. Say the spread and commission total 1.5 pips per trade. The net win drops to 24 pips and the net loss rises to 18.5 pips. The reward to risk falls from 1.5 to about 1.3.

Break even win rate = 1 ÷ (1 + R): 1 ÷ 2.5 = 40% before costs, 1 ÷ 2.3 = about 43.5% after

That is the bar your testing has to clear. A small cost changes it more than most traders expect. See our guide to spreads, commissions and swaps for more on this.

When does the London breakout fail?

• False breaks. Price clears the Asian high, fills buy stops, then falls back through the range. This is the most common loser.
• Wide Asian ranges. If Asia already moved a lot, the stop is wide and much of the day’s move may be used up. The ATR filter exists for this.
• Early news. UK and euro area data released in the London morning can whip price through both sides of the range.
• Quiet days. Around holidays, London may not bring enough volume to carry a break to target.
• Slippage on entry. A buy stop fills at market. In a fast open, the 2 pip buffer can become 4 or 5, which shrinks the reward to risk.

Some traders try a reversal version that fades the first break. That is a different strategy with its own rules. Do not switch between the two after a loss.

How this fits prop firm rules

With one trade per day and a hard stop, your worst normal day is one loss plus slippage. On an example $50,000 account with a $2,500 daily loss limit, $300 of risk uses about an eighth of the limit. The daily limit is not the problem.

The maximum loss is. A strategy that needs to win about 43% of trades will have long losing streaks. With an example $5,000 maximum loss, $300 per trade gives about 16 losses of room. If the drawdown trails, that room shrinks as the floor rises. Size so that at least 10 to 15 losses in a row fit.

• Consistency rules: the fixed 1.5R target caps each win, which helps keep any single day from dominating your profit. See how consistency rules work.
• Minimum trading days: the filters skip many days, so passing may take more calendar time than you expect.
• News rules: skipping news days also keeps you clear of firms that restrict trading around releases.

Rules vary by firm, so check each firm’s page in our forex prop firm list. Then find an account in your budget.

How to test the London breakout

1. Pull at least two years of 15 minute data for one pair. Make sure the chart is set to London time or adjust for it.
2. For each day, record the range size, the ATR, whether it passed the filter, which side filled, and the result in R.
3. Include costs on every trade, and add a pip of slippage to stop entries.
4. Split the results by range size and by year. A rule that only worked in one year is fragile.
5. Forward test on a demo or free trial for at least a month before risking a fee.

Change one rule at a time and keep notes. Tuning many settings until the past looks perfect usually produces a rule set that fails live. Our guide on how to backtest a strategy covers the method in detail.

Questions traders ask

Which pair is best for the London breakout?

GBPUSD and EURUSD are the usual choices, because London is their main session and spreads are tight at the open. Test each pair separately, since they behave differently.

What time does the Asian range end?

There is no official time. Many traders use midnight to 7am London time, and some use 6am or 8am. Pick one, then keep it fixed in testing.

Should I move the stop to break even?

Only if your testing shows it helps. Moving the stop early turns many small winners into scratches, which changes the win rate and the reward to risk.

Trading carries a high risk of loss, and breakout entries can slip at fast opens. Strategy figures here are illustrations, not expected results. Most prop firm accounts are simulated. Nothing here is financial advice.