Veta (sometimes DvegaDtime) measures how an option’s vega changes as time passes — the time decay of your volatility exposure. It’s a second-order Greek that ties volatility sensitivity to the clock.

What veta captures

Vega isn’t fixed over an option’s life — it shrinks as expiration nears (there’s less time for vol to matter). Veta measures that erosion. It’s why a long-dated option has large vega (very volatility-sensitive) while a 0DTE option has tiny vega (a vol move barely changes its price on the last day).

Why it matters

Veta explains a practical fact: on 0DTE, IV changes matter far less to your option than they would on a monthly, because there’s almost no vega left to be moved. Your 0DTE P&L is dominated by delta and theta, not vega. That’s veta at work — it has bled the volatility exposure away.

Veta is why a 0DTE option shrugs off a vol move a monthly would swing on: by expiration day, there’s almost no vega left for volatility to touch.

What it means for a scalper

For a 0DTE scalper, veta’s takeaway is simple: on expiration day you’re trading direction and time decay, not volatility — the IV crush that hurts longer-dated options has little vega left to bite on 0DTE. One more piece of the higher-order Greek map.