Forex Explained / Risk & Position Sizing

Separate notional exposure from the cash supporting it, then see how leverage changes losses and the recovery required after a drawdown.

Exposure is larger than the deposit

Notional exposure measures the size of the underlying position. Margin is collateral required to support it. They are different quantities. A small deposit can support a much larger position, making modest exchange rate movements substantial relative to account equity.

A simple exposure ratio divides notional value by equity, using the same currency for both. A hypothetical $10,000 equivalent exposure supported by $1,000 of equity has a ratio of ten to one. Exact account measures can differ across instruments and offsetting positions.

Trace a loss through the account

If that exposure loses 2 percent of its initial notional value, the loss is about $200 before costs. That equals 20 percent of the original $1,000 equity. The approximation assumes the stated exposure and ignores additional translation effects.

The market does not need to move 20 percent for the account to lose 20 percent. Costs and changing margin requirements can add pressure. Using all available buying power can leave little room for adverse movement or collateral changes.

Margin is a requirement not a risk budget

Initial and maintenance margin rules depend on the instrument and intermediary. If equity becomes insufficient, the account may require additional funds or positions may be liquidated under the agreement. The liquidation price is not necessarily the price you would choose.

Do not infer a maximum loss from the amount deposited. Depending on the product, market move and applicable protections, losses can exceed that amount. Read the specific terms, including closeout rules and any limits on liability. A stop order does not remove gap or execution risk.

Recovery arithmetic is asymmetric

A drawdown is a fall from a previous equity peak. If $1,000 becomes $800, the drawdown is 20 percent. Returning from $800 to $1,000 requires a 25 percent gain. If the value falls to $500, recovering to $1,000 requires a 100 percent gain.

These calculations explain why preserving capital matters independently of a forecast’s appeal. Keep notional exposure, required collateral, planned loss and stress loss as separate figures. Evaluate the whole account rather than assuming each individually small position is harmless.

Check your understanding

An account falls from $2,000 to $1,500. What is its drawdown and the gain needed to recover to $2,000?

See the answer

The drawdown is 25 percent. Recovery requires $500 divided by $1,500, or about 33.3 percent, before costs.

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For education and research. Examples are hypothetical unless identified otherwise. This lesson does not provide personalised investment advice.