Position sizing and the 1% rule: how much to risk per trade

Position sizing is deciding how many shares or lots to trade so that, if your stop loss is hit, you lose only a small, fixed share of your capital. The 1% rule says that share is 1%. With ₹1,00,000 of trading capital, the most any single trade may cost you is ₹1,000, and the number of shares follows from that: 1% of capital divided by the rupees you risk per share.

Why "how much" matters more than "which stock"

Beginners spend nearly all their effort on entries: which stock, which level, which indicator. Almost none goes on quantity. Yet quantity is the only thing that decides whether a wrong trade is a lesson or a disaster.

Two traders can take the identical trade in SBI, with the same entry and the same stop, and one loses ₹500 while the other loses ₹25,000. Same analysis, same outcome on the chart, completely different outcome for the account. The difference was position size, decided before the order.

Trading loses money for most people, and SEBI's own studies have found that around nine in ten individual F&O traders end up with losses. A big part of that is not bad analysis. It is that the losses on the wrong trades are far larger than the gains on the right ones, because nobody sized them.

The 1% rule, stated properly

The rule is often misquoted as "put 1% of your money into each trade". That is not it. The rule is about risk, not position value.

Risk 1% of your capital per trade. Risk means the amount you lose if the stop-loss is hit. The position can be worth far more than 1% of your capital. What is capped is the damage.

Capital here means the money set aside for trading, which you could lose entirely without it changing your rent, your EMIs or your family's plans. Not your savings, not a loan, and not money you will need in the next year.

The formula, with a worked example

Shares to buy = (capital × 1%) ÷ (entry price − stop-loss price)

Say your trading capital is ₹1,00,000, so your maximum risk per trade is ₹1,000. SBI is at ₹500 and the chart gives you a sensible stop at ₹490, just under a support level. Risk per share is ₹10.

Shares = ₹1,000 ÷ ₹10 = 100 shares. Position value is ₹50,000.

Now watch what happens when the stop changes:

• Stop at ₹495, risk ₹5 a share: 200 shares, position ₹1,00,000. Same ₹1,000 at risk.
• Stop at ₹480, risk ₹20 a share: 50 shares, position ₹25,000. Same ₹1,000 at risk.

A tighter stop means a bigger position, not less risk. That is why the stop must come from the chart first, from a level where the trade idea is clearly wrong, and the size must follow. Support and resistance is where most sensible stops live. Never do it the other way round, choosing the number of shares and then squeezing the stop to fit.

When the instrument has a lot size

Options and futures trade in lots, so the smallest possible position is one lot. That changes the question from "how many" to "can I afford one at all".

Suppose the Nifty lot size is 75 at the time you read this (check the exchange's current value). If your stop on a Nifty futures or option trade is 20 points away, one lot risks 20 × 75 = ₹1,500. With ₹1,00,000 capital and a 1% limit of ₹1,000, you cannot take that trade. Not "should not", cannot, if you are following the rule.

This is the honest answer that small accounts do not want to hear. Many F&O trades are simply too large for a ₹50,000 or ₹1,00,000 account. Taking them anyway is where the 90% figure comes from.

Ten losses in a row: 1% versus 10%

Losing streaks are not a sign of a broken strategy. A method that wins 40% of the time will produce ten losses in a row more often than intuition suggests, and over a few hundred trades it is close to certain to happen at least once. What matters is what your account looks like afterwards.

Start with ₹1,00,000 and lose ten trades in a row, each at the same percentage of the current balance.

At 1% per trade:

1. After 1 loss: ₹99,000
2. After 5 losses: ₹95,099
3. After 10 losses: ₹90,438

You are down about 9.6%. To get back to ₹1,00,000 you need a gain of about 10.6%. Uncomfortable, survivable, and you still have almost your whole account to learn with.

At 10% per trade:

1. After 1 loss: ₹90,000
2. After 5 losses: ₹59,049
3. After 10 losses: ₹34,868

You are down 65%. To get back to ₹1,00,000 you need a gain of 187% on what is left. Most people never recover from this, not because the maths is impossible but because the next trades get taken in desperation, at bigger size, to "make it back".

Why losses are harder to recover than they look

Drawdown recovery is not symmetric. The gain needed to recover a loss is always larger than the loss:

• Lose 10%, need 11.1% to recover.
• Lose 20%, need 25%.
• Lose 30%, need 42.9%.
• Lose 50%, need 100%.
• Lose 75%, need 300%.

Keeping each loss small keeps you on the gentle end of this list. That is the entire argument for the 1% rule. It is not about winning. It is about being around long enough for skill to matter.

Adjusting the number

One percent is a ceiling for someone with a tested method, not a target for everyone.

• Complete beginners: 0.5%, or paper trading at zero. The point in your first months is to find out what mistakes you make, and that information is cheaper at small size.
• After a losing streak: drop to half size until you have a few wins with the rules followed. This is not superstition. It stops a bad week from becoming a bad quarter.
• Never above 2%. Above that, the maths of the ten-loss streak starts to look like the 10% column.
• Cap total open risk. If you hold three positions each risking 1%, your account risk is 3%. Many traders cap total open risk at 3 to 5%.

If you are still working out whether trading is for you at all, the free Trading for Everybody course covers this arithmetic before it covers a single chart pattern, and that order is deliberate.

Common mistakes

• Sizing by available margin. The broker's limit tells you what you can take, not what you should.
• "Pura paisa laga do" (put in all the money) on a trade you feel sure about. Feeling sure is not a risk-management input.
• Moving the stop loss further away when price approaches it. This silently turns a 1% trade into a 3% trade. Why most people lose money covers this habit.
• Averaging down. Adding to a losing position doubles the size at exactly the moment the idea is being proven wrong.
• Ignoring gap risk on overnight positions. A stop does not protect you from an opening gap, so overnight trades deserve smaller size than intraday ones.
• Forgetting costs. Brokerage and taxes are a fixed leak. On tiny risk-per-share trades with big quantity, costs can be a large slice of the expected gain.

Key takeaways

• The 1% rule caps the loss per trade at 1% of trading capital, not the position value.
• Shares to buy = (capital × 1%) ÷ (entry − stop). Stop first, size second.
• Ten straight losses at 1% leaves you with about 90% of your account. At 10% it leaves you with 35%.
• Losses need bigger gains to recover; small losses keep the recovery small.
• If one lot risks more than 1% of your capital, the account is too small for that trade.