What Are 0DTE Options? A Plain-English Guide for Day Traders

A few years ago, most options traders bought contracts that expired weeks or months away. Today, a huge amount of trading happens in options that expire the same day they are traded. These are called 0DTE options, short for zero days to expiration, and they have become one of the defining products of modern day trading.

What 0DTE means

Every option has an expiration date. A 0DTE option is simply any option on its final trading day. What changed is availability: S&P 500 index (SPX) options now have expirations every weekday, so traders can find a contract expiring today, every day. Popular ETFs such as SPY and QQQ also offer very short-dated contracts.

How big 0DTE has become

The growth has been dramatic. 0DTE options represented roughly 23% of total U.S. options flow in 2025, according to Northern Trust's options commentary. In the S&P 500 index complex specifically, same-day contracts have at times accounted for more than half of trading volume. Retail traders are a major part of that activity, though their share rises and falls with market conditions: Cboe research found retail's share of 0DTE trading dropped sharply during a volatility spike, then climbed back once markets calmed.

Why day traders use them

• Defined cost when buying. If you buy a call or put, the most you can lose is the premium you paid.
• Leverage. A small premium controls exposure to a much larger amount of the underlying index.
• Precision around events. Traders use same-day options to position around a single data release, Fed decision or earnings-driven move.
• No overnight risk. Positions are resolved by the close, which fits a day trader's flat-by-4 p.m. approach.

The risks are real

Time decay is extreme

An option's value includes time value, which shrinks as expiration approaches. On expiration day, that decay is at its fastest. A contract bought in the morning can lose much of its value by the afternoon even if the market barely moves.

Total loss is common

Out-of-the-money 0DTE options expire worthless if the move you expected doesn't happen in time. Buyers can lose 100% of the premium in hours.

Selling is riskier than it looks

Some traders sell 0DTE options to collect premium, betting that prices stay in a range. That can work often, but a sudden move can produce losses far larger than the premium collected. Selling uncovered options requires a higher level of options approval and margin for good reason.

Volatility can swing fast

Because same-day options react sharply to small price changes, prices can move in big jumps around news. Spreads can widen in fast markets, increasing the cost of getting in and out.

Rules are catching up

The new intraday margin framework that replaced the pattern day trader rule in 2026 explicitly addresses short-dated options, something the 2001 rule never contemplated. Brokers also set their own options approval levels, which determine which strategies you can use.

How to approach 0DTE responsibly

• Understand the Greeks, especially theta (time decay) and gamma (how fast delta changes), before trading.
• Size every position so a total loss of the premium is acceptable.
• Prefer defined-risk structures, like spreads, over selling naked options.
• Avoid holding into the final minutes unless you understand how expiration and settlement work for that product.
• Practice with paper trading first, and journal every trade.

The bottom line

0DTE options are a product of modern market technology: daily expirations, fast electronic markets and zero-commission apps made them accessible to everyone. They can be useful for precise, short-term views, but they compress weeks of risk into a single session. Treat them as a high-risk tool, not a shortcut.