Position sizing for small accounts, explained without the jargon

Position sizing answers one question before every trade: if this trade is wrong, how much do I lose? For a small account the safe answer is usually a fixed, small percentage of the account, commonly one percent. Everything else is just doing the arithmetic, which I will do for you below.

Why sizing matters more than the entry

Most people obsess over where to get in. They hunt for the perfect signal, the exact level, the cleanest setup. But the size of the position, not the entry, decides whether a losing streak is a dent or a disaster.

Two traders can take the exact same trade and have completely different outcomes over a year, purely because one risked a sensible amount per trade and the other bet too big and got wiped out by a normal run of losses. Losing streaks are not a sign something is broken. They are a guaranteed feature of trading. Sizing is how you make sure a normal streak cannot end you.

Survival is the whole game. You cannot compound an account you have blown up.

The one-percent rule, plainly

Risk no more than one percent of your account on any single trade. Read that carefully, because the word that matters is risk, not invest.

Risking one percent does not mean putting one percent of your account into the position. It means structuring the trade so that if your stop is hit, the loss is one percent of the account. You might commit a much larger amount of capital to the position, but the distance to your stop is what caps the loss. Confusing position size with risk is the single most common beginner mistake, and it is the one that quietly does the most damage.

The arithmetic, done for you

Here is the whole calculation:

1. Dollar risk = account size multiplied by 1%.
2. Risk per share = the distance from your entry price to your stop price.
3. Position size = dollar risk divided by risk per share.

That is it. A worked example: a $5,000 account risking 1% can lose $50 on the trade. If your entry is $20 and your stop is $19, the risk per share is $1, so you can buy 50 shares. If the stop is hit, you lose $50, which is your planned 1%.

Account size	Risk at 1%	Stop distance	Shares you can buy
$2,000	$20	$0.50	40
$5,000	$50	$1.00	50
$10,000	$100	$1.50	66
$25,000	$250	$2.00	125

Notice that the number of shares changes with the stop distance, not just the account. A tighter stop lets you hold more shares for the same risk, and a wider stop means fewer. The risk stays fixed at one percent either way. That is the point of sizing off the stop.

What changes on a very small account

On a small account the arithmetic still holds, but two practical things bite harder. First, commissions and fees are a larger percentage of a small position, so a setup that looks fine on paper can be marginal after costs. Second, some trades simply do not size cleanly. If one percent of your account only buys you a handful of shares, the trade may not be worth taking, and there is no shame in skipping it.

This is not a reason to risk more to make trades feel meaningful. It is a reason to be patient and selective while the account is small.

The line I will not cross

No martingale. No averaging down into a loser to lower the average price. No telling myself that just this once, this trade is different and deserves double size. The rule is only a rule if it holds on the trade you most want to break it for, which is usually the one that would have hurt the most.

This is one page of a larger system. The full sizing method, with the journal columns to check it against, is in The 9-to-5 Trader.

Educational only, not financial advice. Trading carries a real risk of loss.