Vol of vol is the volatility of volatility itself — how much the VIX (or implied volatility) is expected to move. Tracked via the VVIX, it can warn of instability beneath a calm surface.

What it measures

The VIX measures expected market movement; vol of vol measures the expected movement of the VIX — a second-derivative gauge. High vol of vol means volatility itself is unstable (traders are paying up for VIX options), even if the VIX is currently low. It’s the market’s uncertainty about its own uncertainty.

Why it matters

Vol of vol can rise before the VIX does — sophisticated players positioning for a volatility spike. A calm, low-VIX tape with rising vol of vol is a tension signal: the surface is calm but someone’s paying for the possibility it breaks (see VVIX as an early-warning tell).

The VIX watches the market; vol of vol watches the VIX. When it stirs under a calm VIX, the calm may be fragile.

The takeaway

Vol of vol (via VVIX) is advanced context — a gauge of how stable the volatility regime is. Not a day-to-day scalping tool, but useful for reading whether calm is genuine or fragile. It rounds out the volatility picture.