Exposure, leverage and margin: three different numbers

Market value, borrowing and collateral

For a simple stock purchase, exposure equals shares multiplied by market price. Equity equals asset value minus borrowing. Initial leverage is exposure divided by equity. A derivative may instead require a contract multiplier; options need further sensitivity analysis, so their face value alone is insufficient.

Securities margin usually involves borrowing money. Futures margin is a performance deposit and is not a down payment on the underlying asset. Both arrangements can require additional funds, but their accounting, financing charges and liquidation procedures differ. Read the specific contract and broker terms.

Worked example: 8% becomes 20%

An imaginary account contributes $12,000 and borrows $18,000 to buy 600 shares at $50. Exposure is $30,000 and initial leverage is 2.5 times. If the shares fall 8% to $46, their value becomes $27,600. Assuming unchanged debt and no costs, equity falls to $9,600: a 20% loss.

Leverage then rises to $27,600 / $9,600 = 2.875 times even though no shares were added. This changing denominator explains why a declining account can become more fragile without any new trade. Interest and transaction costs would reduce equity further.

Why the deposit is not the loss limit

The collateral requirement is neither a promised exit price nor a maximum loss. A broker may raise its requirements or liquidate positions under its agreement. Gaps can produce losses beyond initial equity. A leverage ratio also hides concentration: two equally leveraged accounts can have very different risks.

Apply a closed-bar stress scenario

On an available closed daily, weekly or monthly chart, record a historical adverse move and apply that percentage to a hypothetical position value. Keep this market scenario separate from the broker margin calculation. Student Wyckoff Pro can support closed-bar analysis; the exposure calculation and account decisions remain outside that chart exercise.

Primary sources

Sources explain the mechanics and limitations; the editorial examples use invented numbers rather than market quotations.

• Investor Bulletin: Understanding Margin Accounts

Sources checked: 2026-10-23