Pair traders hunting for an edge might want to focus on a little-known gauge tied to bitcoin BTC$91,896.57 and the S&P 500.

That gauge is the spread between Volmex’s BVIV – the 30-day implied volatility index for BTC – and its S&P 500 counterpart, the VIX index. The spread has started to widen again, suggesting BTC volatility is expected to outpace equity market risk.

Implied volatility is influenced by demand for options or hedging instruments.

"When the BVIV-VIX spread widens, it typically signals that markets expect higher volatility in crypto than in equities," Volmex's Founder Cole Kennelly told CoinDesk. "Crypto options markets adjust more rapidly to liquidity and macro catalysts, so implied volatility often moves ahead of traditional markets."

The spread recently broke out of a months-long range play between 20.000 and 32.000 and pierced the downtrend from March 2024's peak. These patterns suggest that BTC is likely to see more volatility than the S&P 500 in the coming days.

Prospects of BTC volatility becoming relatively richer compared to the S&P 500 may draw pair traders to consider opposing volatility bets in BTC and the S&P 500.

"When the BVIV–VIX spread widens meaningfully, some traders view it as a relative value setup: crypto implied volatility has cheapened or richened relative to equity volatility. This type of view is typically expressed through multi-legged cross-asset volatility trades rather than a simple directional position," Kennelly explained.

Trading volatility, a capital-intensive strategy, involves betting on price swings rather than direction, typically through non-directional options or volatility futures.

It goes without saying that these strategies are risky, like other plays, and require constant monitoring of positions and ample capital, which makes them suitable for institutions.