0DTE Options Trading Foundations

Understanding Same-Day Expiration Options, Greeks, and Risk in Modern Markets

0DTE options and same-day expiration options can behave very differently from longer-dated contracts. With little time left, option premiums may respond quickly to small price changes, shifts in implied volatility, and changing liquidity. 0DTE Options Trading Foundations offers a clear, beginner-friendly explanation of these mechanics, with a steady focus on interpretation and risk.

Topics include:

• What 0DTE means and why same-day expiration can feel “compressed”

• The option contract in plain English, including intrinsic vs extrinsic value

• Bid, ask, spreads, and why the “price” is often a range

• Time decay near expiration and why theta is not a simple countdown

• Delta and gamma as practical ways to understand sensitivity and changing sensitivity

• Implied vs realized volatility and why premiums can move on a quiet chart

• Payoff shapes and why risk can feel concentrated in short time windows

• Market regimes (trend, range, news-driven, quiet) and how context changes behavior

• Common beginner misreads and a simple framework for study and vocabulary-building

• Fictional illustrative scenarios designed to make abstract concepts easier to recognize

This book is educational in nature and is intended to help readers understand how 0DTE options pricing can behave in modern markets. It does not provide personalized financial advice or promise outcomes.