Basics

Margin Call

By Ryan Silk & Lawrence Polatchek · Reviewed April 2026 · Options Trading Glossary

Broker demand for additional account funds

What is Margin Call?

Margin Call A broker's demand that an investor deposit additional funds or securities when the account equity falls below the required maintenance margin. Naked option positions and short stock can trigger margin calls during adverse moves. Defined-risk spreads significantly reduce margin call risk.

Complete Definition

A broker's demand that an investor deposit additional funds or securities when the account equity falls below the required maintenance margin. Naked option positions and short stock can trigger margin calls during adverse moves. Defined-risk spreads significantly reduce margin call risk.

Example

You sold naked puts and the stock dropped 20%. Your broker issues a margin call requiring you to deposit more funds or close positions.

Related Terms

Margin Naked Options Maintenance Margin Buying Power

Written by

ApexVol Research Team

Quantitative options research

All calculations use live ORATS institutional data — the same source used by professional volatility desks.

Technical reviewer

Ryan Silk, ApexVol Founder

Reviewed for technical accuracy

10+ years trading options. Built ApexVol's pricing engine, Greeks model, and IV-rank methodology.

This guide is updated as market conditions and ORATS data change. Last revised 2026-05-12. How we research →

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