Position sizing is the one calculation that separates traders who last from traders who do not, and it takes about fifteen seconds. It answers a single question: given how much I am willing to lose on this trade and where the idea becomes wrong, how much can I buy?
Position size equals account risk divided by trade risk. Account risk is your balance multiplied by the percentage you are prepared to lose on one trade — commonly 1%, sometimes 2%, rarely more for anyone still learning. Trade risk is the distance in price between your entry and your invalidation level.
Notice what the formula does not contain: your confidence, the signal's confidence score, or how good the setup looks. Those belong in the decision to take the trade at all, not in how large it is. Increasing size because a setup looks especially good is the most common way a good month becomes a bad year.
Forex: a 10,000 USD account risking 1% gives 100 USD of account risk. If the stop is 25 pips away on EUR/USD, and one standard lot moves roughly 10 USD per pip, then 25 pips costs 250 USD per lot. 100 divided by 250 is 0.4 lots.
Crypto: a 5,000 USD account risking 1% gives 50 USD. If Bitcoin is at 60,000 and the invalidation sits at 58,200, the trade risk is 1,800 USD per coin. 50 divided by 1,800 is 0.0278 BTC — about 1,667 USD of exposure, which is 33% of the account despite risking only 1% of it. That gap is exactly why the calculation is necessary.
Stocks: a 20,000 USD account risking 1% gives 200 USD. A stock at 48.00 with a stop at 46.50 has 1.50 of trade risk per share. 200 divided by 1.50 is 133 shares.
Moving the stop after entry converts a calculated risk into an unknown one, and it is almost always done in the direction that increases loss. Decide the invalidation level before you enter and treat it as fixed.
Ignoring correlation is the quieter mistake. Three positions each risking 1% in instruments that move together is one position risking 3%. Add up exposure by driver — dollar strength, index direction, Bitcoin beta — not by ticker.
Increasing size after losses to recover is the fastest of all. A drawdown demands smaller positions, not larger ones, because the account has less capacity to absorb another loss.
Safabot's Tools section includes free position size, pip value, risk-to-reward and margin calculators, open without an account. Use them until the calculation is automatic, then keep using them anyway — the discipline of doing it is most of the benefit.
Safabot is educational software and does not provide investment advice. Trading carries the risk of losing your capital.
Position size = (account balance x risk percentage) / distance from entry to your invalidation level. Risk percentage is commonly 1% per trade.
One percent of account equity is the common benchmark for traders who are still building consistency. Higher fixed percentages shorten the losing streak needed to do serious damage.
No. A drawdown means the account can absorb less, so positions should get smaller. Increasing size to recover is how manageable losses become unrecoverable ones.
In practice yes. A modest edge with disciplined sizing compounds; a strong edge with erratic sizing can still end at zero, because ruin is permanent and edge is only statistical.