Goldman Sachs Group Inc.’s decision to buy Innovator Capital Management in a deal worth $2 billion is delivering a massive payday to the exchange-traded fund issuer’s founders.

Vanguard Group, the world’s second-largest asset manager, has decided to allow ETFs and mutual funds that primarily hold cryptocurrencies to be traded on its platform, reversing a longstanding position.

Goldman Sachs Group Inc. will pay $2 billion to buy Innovator Capital Management, a deal that combines the bank with an issuer of a relatively new type of exchange-traded fund that has caught the attention and ire of some on Wall Street.

Private equity firms, struggling to find buyers for their investments, are turning to an old playbook like never before.