A 0DTE (zero-days-to-expiration) option expires today; a 1DTE expires tomorrow. One day apart, but the way they move — and the way they can hurt you — is very different.

0DTE: maximum gamma, brutal theta

At 0DTE, an at-the-money option is almost pure gamma — small moves in the underlying swing the option's value hard, which is the appeal for scalpers. The flip side is savage theta: the premium bleeds fast, and a flat hour can gut a position even when you're eventually right on direction (theta decay). Everything resolves by the close — nothing is held overnight, which is both the discipline and the constraint.

1DTE: a cushion, and overnight risk

A 1DTE option carries more extrinsic value, so theta is slower and a stalled trade has room to breathe (1DTE scalp mechanics). The trade-off is real: you're exposed to overnight gaps, and the gamma isn't as explosive as a same-day contract at the close.

0DTE punishes hesitation; 1DTE forgives it — but charges you overnight risk for the mercy.

How to choose

Trade 0DTE when you want tight, same-day risk with force-flat-by-close discipline and can act decisively on stalls. Trade 1DTE when you want a little cushion and can accept overnight exposure. NoVo makes this an explicit dial — your DTE Target sets the whole risk profile — and the difference in decay is exactly why the two need different exit tempo. See gamma risk on 1DTE and position sizing for 0DTE.