0DTE options scanner for same-day contract review.

Why same-day contracts behave differently

A zero-days-to-expiration contract is a different instrument from the same strike with a month of life, even though the chain lists them identically. With hours remaining, extrinsic value collapses toward zero and the option's price becomes almost entirely a function of how far the underlying sits from the strike.

That compression is what draws traders and what punishes them. Gamma is at its highest near the money on expiration day, so an option's delta can travel from near zero to near one on a modest move in the underlying. The same mechanism runs in reverse with equal speed.

Time decay on the final day is not the gentle daily erosion of a longer-dated position. An at-the-money contract can lose the majority of its remaining value inside a single afternoon with the underlying essentially unchanged.

What a 0DTE scan should filter on

Standard flow filters translate poorly to same-day contracts. Open interest is frequently small or newly created, which makes V/OI ratios volatile and easy to misread. A contract with 30 open interest trading 3,000 times produces an enormous ratio that mostly reflects an empty denominator.

Liquidity deserves more weight than usual. Bid-ask spread is the cost you pay twice, and on a contract worth twenty cents a two-cent spread is ten percent of the position gone at entry. Spreads widen sharply into the final hour precisely when volume looks most attractive.

• Absolute volume, weighted more heavily than V/OI, because the open-interest denominator is unreliable intraday.
• Bid-ask spread as a proportion of contract price — the round-trip cost, not a rounding error.
• Distance from the strike, since a few dollars decides whether the contract expires worthless.
• Whether a scheduled event lands inside the remaining hours.

Index versus single-stock same-day contracts

Most 0DTE volume concentrates in index and index-ETF products, which list daily expirations and carry the liquidity to support them. Single-stock names typically expire weekly, so a same-day single-stock contract exists only on its weekly expiration date.

That difference matters for interpretation. Index same-day flow reflects hedging and short-horizon positioning against a broad basket. Single-stock same-day flow on a Friday is a narrower and often noisier signal, frequently reflecting position management into expiration rather than a directional view.

ConvexRadar leads with stocks and shows a single index read for market context rather than filling the list with index products.

The honest risk framing

Same-day options are the highest-variance instrument retail traders routinely access. The convexity that makes a small position capable of a large percentage gain is the same convexity that makes total loss the ordinary outcome rather than the tail case. A contract that expires a dollar out of the money is worth nothing, no matter how correct the thesis was an hour earlier.

ConvexRadar surfaces which same-day contracts are seeing unusual activity and what the surrounding context looks like. That is research context. It is not a prediction of direction, a recommendation to trade, or an assessment of whether same-day options suit your situation. Position sizing and risk management remain entirely yours, and on this particular instrument they matter more than the entry.