Basics

Stock

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

Share of ownership in a company

What is Stock?

Stock A share of ownership in a publicly traded company. Stocks are the most common underlying asset for listed options contracts. Each standard equity option contract represents 100 shares of the underlying stock.

Complete Definition

A share of ownership in a publicly traded company. Stocks are the most common underlying asset for listed options contracts. Each standard equity option contract represents 100 shares of the underlying stock.

Example

You own 100 shares of AAPL stock at $150/share. You could sell a covered call against those shares to generate income.

Related Terms

Underlying Contract Covered Call

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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