Exclusive: NYSE parent company invests in crypto exchange OKX at $25 billion valuation as part of push into blockchain-based stocks

Last summer, Haider Rafique flew out to Atlanta to meet with the chairman of the New York Stock Exchange. What was supposed to be a 30-minute chat turned into a four-hour marathon conversation, recalled Rafique, the global managing partner of corporate affairs at OKX, one of the world’s largest crypto exchanges.

Fast-forward a few months and what started as an informal chat became a series of meetings, intense due diligence, and eventually a mammoth deal. Intercontinental Exchange, the...