Brian Armstrong, CEO of Coinbase, speaking on CNBC's Squawk Box outside the World Economic Forum in Davos, Switzerland on Jan. 21st, 2025.Gerry Miller | CNBCCoinbase is joining the S&P 500, replacing Discover Financial Services in the benchmark index, according to a release on Monday. Shares of the crypto exchange jumped 8% in extended trading. The change will take effect before trading on May 19. Discover is in the process of being acquired by Capital One Financial.Since going public through a ...