By Pranav Kiran

Ken Griffin is trying to tame cryptocurrency’s frontier. The founder of market-making giant Citadel Securities, alongside Jane Street and others, is investing $800 million in Kraken at a $20 billion valuation as it heads toward a public listing. Pairing with Griffin’s other big bet on providing liquidity for crypto trades could help to smooth out a still-clunky market. If digital speculation steps closer to traditional finance’s reliability, orders coursing through the system could also prove lucrative.

Cryptocurrency markets differ from old-world securities. In equities, brokerages and exchanges are typically separate. In crypto, they’re often under the same roof, with an exchange controlling both trading…