The martingale is a betting system: after every loss, you double your next bet, so that a single win recovers all prior losses plus a small profit. On paper it looks foolproof — you always come out ahead when you finally win. In reality, it's one of the most reliable ways to blow up an account.
The seductive math
The logic is genuinely tempting. Lose $100, bet $200; lose that, bet $400 — win once and you recover everything plus your original stake. Since you'll "eventually" win, it feels like guaranteed profit. Applied to trading, it looks like averaging down: add more to a loser, lower your average, and a small bounce makes you whole.
Why it always breaks
Two things kill the martingale. First, your capital is finite — a long enough losing streak requires a bet larger than your entire account, and losing streaks are guaranteed given enough trades. Second, real trading has no reliable "you'll eventually win" — a trend can run against you far longer than you can double. The strategy converts many small wins into one catastrophic, account-ending loss. It maximizes risk of ruin.
The martingale works every time — right up until the one time it takes everything you have.
Spotting the disguises
Martingale thinking hides in trading behavior: doubling down on losers, "revenge" sizing up after a losing streak to win it back fast, or grid strategies that add on every adverse move. All share the fatal DNA — increasing risk as you lose. The disciplined opposite is fixed, small position sizing that reduces exposure into losses. A mechanical system never doubles down to feel better — which is exactly why it survives the streak the martingale can't.