How Long Can a Losing Streak Last?

You're on your 8th loss in a row, and you're starting to wonder if your system quit working. I've been there. Usually the next move is to start tweaking: tighter stop, different setup, skip the open.

Sometimes the system really is broken. But a long losing run can also come from plain bad luck, and that happens more often than most people think. What helps is knowing how long a losing run can get for your win rate, before you change anything.

Losing streaks are mostly about order

Here's an easy way to see it. Take your trades and shuffle them like a deck of cards. Same wins, same losses, just a different order.

Order 1: 4 wins, 6 losses

WLWLL WLWLL

Longest losing run: 2

Order 2: the same 4 wins, 6 losses, shuffled

WWLLL LLLWW

Longest losing run: 6

Both rows add up to the same thing. The only difference is where the losses landed. That's why a streak says less about your system than it feels like it does in the moment.

A table you can use today

I ran the shuffle for a few common win rates. Each number below is the longest losing streak you'd see in 19 out of 20 shuffles. I call that a normal bad run. If your streak is at or under it, bad luck can explain it on its own.

Win rate	50 trades	100 trades	200 trades	500 trades
35%	12	14	16	18
40%	11	12	14	16
50%	8	9	10	12
60%	6	7	8	9

Coin-flip math, 20,000 shuffles for each cell. Not trading results. Darker = longer normal streak. The outlined cell is the example below.

↓

Lower win rate, longer streaks

At a 40% win rate, 12 losses in a row over 100 trades is still in the normal range. Ugly, sure. But 40% does that sometimes.

→

More trades, longer streaks

Trade long enough and you'll hit a run longer than any you've had, even if nothing about your trading changed. Your "worst ever" streak only goes one way.

Find your own longest streak in Excel

This part takes about a minute. It assumes your log has one row per trade, with the profit or loss in column B.

In cell C2, type =IF(B2<0, N(C1)+1, 0)
Copy that cell down to your last trade.
In any empty cell, type =MAX(C:C). That is your longest losing streak.

Then look up your win rate and trade count in the table and see where you land.

Break-even trades are your call. If you count them as losses, change B2<0 to B2<=0.

The catch The shuffle treats every trade like a coin flip, with no link to the trade before it. People aren't coins. If you size up after a loss, or start forcing trades when you're frustrated, your real streaks can run longer than the table says.

So the table only answers one question: could this be bad luck? If yes, maybe give it some time before you touch your rules. And if you're past the normal range, that doesn't automatically mean the system is broken either. It just means it's worth a closer look.

Write two numbers down

My suggestion: work these out now, while things are calm.

NUMBER 1

Normal bad run

How many losses in a row is normal for your numbers. The table gets you close.

NUMBER 2

Normal bad slump

How far your account can drop from a high, in dollars, and still be inside normal. Here's how to check it.

Then when a bad week shows up, you're checking it against numbers you picked with a clear head. Not ones you made up in the middle of a drawdown.

I built LogBench partly to run this shuffle on my own trades: real wins and losses, in dollars, 5,000 times. It reads the Excel or CSV log you already keep and runs on your computer. Nothing gets uploaded.

This article is general math, not trading advice.