Bitcoin-Volatility Collapse Forces Risk-Loving Traders Elsewhere

Bitcoin, once the unruly child of finance, is showing signs of maturity as its wild swings fade, forcing speculative traders to hunt for a new playground.

The world’s biggest cryptocurrency is behaving more like a blue-chip stock as Wall Street’s buy-and-hold investors plunge in. Annualized volatility has dropped to a once-unthinkable 38% from close to 200% more than a decade ago. It is now comparable to the likes of Starbucks Corp. or Goldman Sachs Group Inc., according to Bytetree Asset Management.

Investors chasing price swings are instead turning to rival Ethereum, the second-largest virtual currency. On several ...