What is leverage in trading?

Leverage is the ratio between position size and margin held. At 1:30, every $1,000 of margin controls a $30,000 position. At 1:100, every $1,000 controls $100,000.

The trader does not borrow capital from the broker in the conventional sense. The position is synthetic — it mirrors price movement on the underlying instrument without transferring ownership. Margin is collateral against adverse movement, not a loan that incurs separate interest. Holding a forex position overnight does incur swap, but swap reflects the interest rate differential between the two currencies in the pair, not interest on borrowed money.

The common description of leverage as "borrowing from your broker" is loose. No capital changes hands. The mechanics are closer to a synthetic futures position than to a margin loan.

For a USD account opening 1 standard Lot size of EUR/USD at 1.0850 with 1:30 leverage (the ESMA cap for major FX in the EU and UK):

Account currency

USD

Instrument

EUR/USD

Lot size

1.00 standard

Entry price

1.08500

Leverage

1:30 (ESMA cap)

The margin is reserved capital, not a cost. It is returned to the account when the position closes, regardless of profit or loss. The cost of opening the position is the Spread, which is separate from margin entirely.

Higher leverage does not change the position size. At 1:100 (available outside the EU and UK), the same 1-lot EUR/USD position holds only $1,085 in margin. The position behaves identically; the difference is how much capital is reserved versus available as free margin.

A 100-pip adverse move on a 1 standard lot EUR/USD position is a $1,000 loss, regardless of leverage. The underlying P&L is determined by pip count and Pip value, not by leverage.

What leverage changes is what that loss represents as a percentage of margin held. At 1:30 with $3,617 margin, the $1,000 loss is 27.6% of margin. At 1:100 with $1,085 margin, the same $1,000 loss is 92.2% of margin — wiping out almost all of it.

The effect on the account depends on free margin. With $10,000 account equity and $3,617 margin held (1:30), the $1,000 loss is 10% of equity. With the same $10,000 equity and $1,085 margin (1:100), the $1,000 loss is still 10% of equity — but the position can be sized 3× larger before margin is fully reserved, allowing 3× the loss exposure if the trader takes that opportunity. Leverage does not amplify loss probability; it amplifies the size of every outcome the trader sizes into.

A margin call triggers when account equity falls to a defined fraction of margin held — typically 50% on retail brokers. At the trigger, the broker closes positions automatically (largest losing first) until equity rises above the threshold.

Worked example: opening 1 lot EUR/USD at 1.0850 with $10,000 equity and 1:30 leverage. Margin held = $3,617. Margin call triggers when equity falls to 0.50 × $3,617 = $1,808.50 — a loss of $8,191.50, or 819 pips of adverse movement.

The trader's Stop-loss is the price-controlled exit. The margin call is the broker's mechanical floor. They serve different functions: a stop-loss closes the position at a chosen price; a margin call closes whatever positions are open to bring equity above the broker's threshold. Margin calls execute slower than stop-losses and at market price, not at a chosen level.

ESMA caps retail leverage at 1:30 for major FX, 1:20 for non-major FX and gold, 1:10 for non-gold commodities and major equity indices, 1:5 for individual equities and minor indices, and 1:2 for cryptocurrencies. The caps apply to retail clients in the EU and UK.

The caps are not broker policy. They are regulatory floors. Brokers offshore the same instruments at higher leverage to non-EU and non-UK retail clients — the regulator's protection ends at the jurisdiction's edge.

The reason for the caps is statistical. The retail loss data published by EU brokers shows that 70–80% of retail accounts trading CFDs lose money over a given quarter. Lower leverage caps reduce the size of average losses without changing the underlying loss rate.