peshkov/iStock via Getty Images Michael Sonnenshein, CEO at Grayscale Investments, said Thursday that SEC approval of a Bitcoin ETF "is a matter of when, not a matter of if." Sonnenshein told CNBC that regulators have remained "highly engaged" with the industry during the approval process for a Bitcoin ETF, raising his confidence that an official blessing will come eventually. The Grayscale CEO predicted that approval of a Bitcoin ETF would open the door to ETFs based on other digital assets as well. On the crypto market in general, Sonnenshein reported that clients have shown an increased appetite for diversification within the asset class. He noted that many clients make their first crypto purchase with either Bitcoin (BTC-USD) or Ethereum (ETH-USD) but often move on to lesser-known names, such as stablecoins. "A lot of investors are getting excited about all of the new and differentiated use-cases that are popping up around