Leverage is the ratio of position size (notional exposure) to account equity, expressed as N:1. It allows a trader to control more capital than their balance — for example, with 30:1 leverage, $1,000 of equity can control $30,000 of currency. Leverage is provided by the broker as margin financing; the account equity acts as collateral. Gains and losses are calculated on the full notional exposure, so a 1% move on a 30:1 leveraged position is a 30% swing on the account.
Leverage by itself is neither good nor bad. It is a multiplier on whatever the underlying strategy already does. The misconception is that higher leverage means higher expected return; it does not. It only widens the variance and shortens the path to either profit or zero.
Formula
Leverage = Notional exposure / Account equity
Margin used = Notional exposure / Leverage offered
Worked example
Account equity: $5,000. Broker offers 30:1 leverage. You open 1.0 standard lot of EUR/USD at 1.0850 (notional = $108,500).
- Effective leverage used: $108,500 / $5,000 = 21.7:1
- Margin locked: $108,500 / 30 = $3,617
- A 50-pip adverse move = $500 loss = 10% of equity
- A 250-pip move = $2,500 = 50% of equity, triggering most prop firm and broker margin calls
Why it matters
High leverage doesn't increase expected return — it compresses the timeline to ruin. A strategy with a true 0.3% per-trade edge produces the same long-term geometric growth at any leverage level, but at high leverage a normal losing streak (which is statistically inevitable) wipes the account before the edge can express itself.
Common pitfalls
- Confusing offered leverage (30:1) with used leverage — what matters is how much you actually deploy.
- Sizing positions to broker margin limits rather than to a fixed account-risk percentage. See position sizing.
- Increasing leverage after losses to "make it back" — the fastest known route to a zero balance.