Every few months someone sends me a description of "a system that cannot be beaten": after every loss you double the position, so the first win recovers everything and leaves a profit. That is martingale — a rule from the eighteenth-century French gaming salons that has been ruining players ever since. On the currency market it works faster than at a roulette table, because transaction costs and margin requirements are added to the arithmetic. Below I show, in numbers, exactly where the system breaks.

What martingale actually is

The whole construction rests on one assumption: if the probability of winning is roughly constant on every attempt, sooner or later you will win. And if each successive stake is twice the previous one, a single win covers the sum of all earlier losses and leaves a profit equal to the opening stake.

The classic martingale sequence
Trade 1Stake $1, loss. Balance: −$1.
Trade 2Stake $2, loss. Balance: −$3.
Trade 3Stake $4, loss. Balance: −$7.
Trade 4Stake $8, loss. Balance: −$15.
Trade 5Stake $16, loss. Balance: −$31.
Trade 6Stake $32, win. Covers $31 of losses and leaves $1.
Result of the sequence+$1, exactly the size of the opening stake

The arithmetic checks out, and that is precisely where the trouble starts. Martingale is not a mathematical swindle — it really does close every sequence in profit. Provided you have unlimited capital and nobody caps the size of your position. Neither condition is true.

Where exactly the system breaks

Position size grows exponentially while the account balance does not grow at all. The calculation below runs on EUR/USD, where the pip value on a 0.01 lot position is $0.10 and the stop loss sits at 20 pips — so the first loss is exactly $2.

A $10,000 account, starting at 0.01 lot, eight losses in a row
After 1 lossposition 0.02 lot, cumulative loss $2
After 3 lossesposition 0.08 lot, cumulative loss $14
After 5 lossesposition 0.32 lot, cumulative loss $62
After 7 lossesposition 1.28 lot, cumulative loss $254
After 8 lossesposition 2.56 lot, cumulative loss $510

The losses themselves do not look frightening — after eight defeats in a row the account still holds $9,490, more than 94 percent of the starting capital. The dangerous one is the ninth position. It runs to 2.56 lots, which is €256,000 of notional value. At the maximum 1:30 leverage that the ESMA rules allow a retail client on major pairs, the required margin is roughly €8,500 — around $9,200 at an exchange rate near 1.08.

On an account holding $9,490, opening that position leaves under $300 of free equity. The position loses that much on a 12-pip move against it. So before price even reaches the stop loss, the broker closes the trade at the stop-out level. Not because the trader misread the chart — because the arithmetic of doubling caught up with the size of the account.

Why it seems to work for months

Short losing streaks are frequent and long ones are rare, and the illusion lives on that difference. Two or three losses in a row happen every week, and every time the doubled position really does recover the loss. The account grows slowly but very evenly, the equity curve is as smooth as a ruler, and after a few months the trader is convinced they have found something the rest of the market has missed.

That smooth curve is not evidence that the system works. It is evidence that the run of eight losses has not arrived yet. All the profit built up over six months is, in this arrangement, an advance the market pays out early and takes back in a single sequence.

When the run of eight losses arrives

Take for a moment the friendliest possible assumption: trades are independent and the chance of winning is exactly one half. On that model, a run of eight consecutive losses takes on average around five hundred trades to appear. A trader placing a hundred trades a month will therefore meet it roughly once in a bit over a year — and "on average" also means it could just as easily turn up in week three.

In practice it is worse than the model, for two reasons. Systems built on a tight stop rarely win half their trades, and every percentage point below fifty shortens the expected wait. More importantly, currency rates do not behave like coin flips: in a clear trend, trades taken against the direction of the market lose in runs, because the same mechanism keeps beating them rather than chance.

I am not going to quote a percentage of accounts that end at zero, because no public statistic separates traders using martingale from everyone else. What is known is the loss distribution across the whole retail segment — brokers supervised under the ESMA rules must publish the share of accounts losing money, and it usually falls between 74 and 89 percent.

Why currencies are worse than roulette

On European roulette, backing a colour gives you 18 chances in 37, slightly below half. On the currency market the conditions are less favourable, even though at first glance they look similar:

  • The spread — every successive position opens at a loss equal to the gap between the buying and the selling price, and since positions double, so does the cost.
  • Swap points — a position carried overnight is charged a financing cost that stops being a rounding error once the volume is large.
  • Slippage — the bigger the position and the faster the market, the greater the chance the order fills worse than assumed.
  • Margin — it is margin, not the account balance, that sets the real limit. An exponentially growing position needs exponentially growing collateral.
  • Trends — a market that runs one way for three weeks produces exactly the losing streaks this system cannot survive.

There is one piece of good news, and it comes from regulation: a retail client in the European Union has negative balance protection, so you will not walk away from the account owing the broker money. You lose everything you deposited, but no more than that.

"Recovery" robots — how to spot the trap being sold

Martingale sits underneath most of the automated systems sold on social media, though it is almost never called by its name. The advertisement usually reads the same way: a high win rate in a historical test, a price of a few hundred dollars, a promise of profit without supervision. The pattern repeats:

  1. The historical test covers a period without a clear trend — precisely the conditions in which doubling works best.
  2. For the first few months on a live account the robot posts a steady, modest profit and builds trust.
  3. A trend arrives, the losing streak builds, and position size outgrows what the account can carry.
  4. The account is closed out at stop-out level, and the seller puts it down to "unusual market conditions".

The practical rule is simple: if the description of a robot contains the words "recovery", "grid", "averaging" or a position multiplier after a loss, you are looking at martingale, whatever it has been named. A program that increases risk after a defeat is not a strategy — it is a deferred loss.

Anti-martingale, or the logic reversed

There is an approach that does the exact opposite: increase position size after a run of wins and cut it after losses. It is called anti-martingale, and its fundamental advantage is that during a losing streak the risk shrinks by itself, so the account cannot be closed out by a single sequence.

The price is a less tidy equity curve — a good run is followed by larger setbacks, because that is when the position is largest. Most professionally used systems are a variant of this approach: fixed risk expressed as a percentage of capital, or position sizing scaled by the Kelly criterion. None of them promises a sequence that always ends in profit, and that is exactly their merit.

What to do tomorrow

  1. Review your trade history for position size. Export the last three months from the platform and check whether the volume of the next trade was ever larger after a loss than after a win. If it was, you are using martingale, even if you have never called it that.
  2. Work out the longest losing streak your account survives at fixed risk. At 1 percent of capital per trade, ten losses in a row cost just under 10 percent of the balance. Write that number down next to your desk — it is the benchmark against which you compare every new idea about position management.
  3. Set a fixed risk figure in your position calculator and stick to it for a month. Before every order, work the volume out from the stop distance and your chosen percentage of capital instead of deciding it on the basis of the previous result.
  4. Check the documentation of every automated system connected to your account. Look for the words "recovery", "grid", "averaging" and any position multiplier. Disconnect from the live account any program that contains them, before you find out what its eighth position in a sequence looks like.