The instrument is unforgiving, but the mistakes are predictable. Learn them here instead of paying tuition for each.

1. Oversizing

The number-one killer. A 0DTE option can go to zero in an afternoon, so a too-big position turns one bad trade into a catastrophe. Size for the zero (0DTE position sizing).

2. Trading the lunch chop

Midday, volume dies and the tape chops while theta keeps bleeding. Forcing trades into a dead 11:30–1:30 tape is how accounts leak out. Often the best trade is none (the best windows).

3. Holding into the close

Hoping a losing 0DTE comes back into expiration turns a manageable loss into a total one — and lets a winner round-trip to zero. Flatten before the bell (0DTE risk management).

Every classic 0DTE blow-up is the same trade: too big, too late in the day, held too long, hoping.

4–5. Chasing and ignoring theta

Chasing: buying an extended move after it's already run, right as it's set to reverse — you pay the top and eat the pullback (chasing the entry). Ignoring theta: treating a flat position as neutral when it's actually bleeding every minute — the reason a time-stop matters (why theta accelerates). Discipline on all five is exactly what automation enforces better than a human can.