RVX is the CBOE Russell 2000 Volatility Index — the same 30-day forward implied-volatility calculation as the VIX, run on Russell 2000 (IWM) options instead of S&P 500 options. In one number it tells you how much movement the market is pricing into small-caps over the next month.
Why RVX usually sits above the VIX
Small-caps are simply more volatile than large-caps. They carry more leverage, more sensitivity to credit and rates, and thinner liquidity, so the market prices a bigger range into them. That's why RVX typically trades above the VIX — a spread of several points is normal, and it widens when risk appetite sours (small-caps get sold first) and compresses in broad, calm risk-on tapes. The RVX–VIX spread is itself a risk-sentiment tell: a blowout means the market is singling out small-caps for stress.
Why it matters for IWM 0DTE
The expected move — the straddle-implied range for the session — scales with implied volatility. If you gauge IWM's expected move off the VIX, you understate it, because the VIX measures the calmer S&P. Flooring IWM on RVX instead gives you a range that reflects the vehicle you're actually trading: wider stops, walls that sit proportionally further out, and a gamma flip whose distance you read against the right vol surface. Using the wrong volatility index is how a small-cap scalp gets stopped by "noise" that was always inside the true expected move.
Sizing IWM off the VIX is like using the speed limit from the next road over. RVX is small-caps' own number — it's the one that frames the range you're actually trading.
The three-index volatility map
Each of the big 0DTE markets has its own gauge: the VIX for SPY (S&P 500), VXN for QQQ (Nasdaq-100), and RVX for IWM (Russell 2000). They move together in a crisis but carry persistent level differences — VXN and RVX both structurally above VIX — and their spreads tell you where the market is putting its fear: tech, small-caps, or broadly. Reading the right one for the ticker in front of you is the difference between a sized risk and a guessed one.
How NoVo uses RVX
When you set IWM as your NoVo execution ticker, the engine floors IWM's expected-move and gamma-flip weighting on RVX rather than the VIX (QQQ uses VXN; SPY uses the VIX) — so the IWM dealer map respects small-cap volatility instead of understating it. It's a small piece of a larger principle: read each of the three mastered tickers on its own terms. If you're weighing which to trade, see SPY vs IWM for 0DTE and picking your one ticker.