Win/Loss Streak Probability Calculator

Streak probability calculates how likely you are to experience a consecutive run of wins or losses.

Probability of a streak of length N: P(streak) = Rate^N

Where Rate = win rate for win streaks, or (1 − win rate) for loss streaks.

Probability of a streak occurring within S trades: P(at least one streak in S trades) ≈ 1 − (1 − Rate^N)^(S − N + 1)

Loss streak reality check (at 50% win rate):

• 5 losses in a row: 3.1% per sequence, but nearly guaranteed over 100 trades
• 7 losses in a row: 0.78% per sequence, likely over 500 trades
• 10 losses in a row: 0.098% per sequence, happens over thousands of trades

Why this matters:

• Every trading system WILL experience streaks
• A 10-trade losing streak at 2% risk = 18.3% drawdown
• Knowing the probability helps you size positions for survival
• If you cannot emotionally handle the expected worst streak, reduce risk