Grayscale Bitcoin Trust (GBTC) operates as a closed-end fund that holds Bitcoin, and its shares trade at a premium or discount to the net asset value (NAV) of the underlying Bitcoin. The approval of a Bitcoin ETF could provide investors with an alternative means of gaining exposure to Bitcoin, which could impact GBTC's premium or discount to NAV. The direction of the impact is uncertain, as it could either lead to a narrowing of the discount if investors anticipate a conversion of GBTC to an ETF, or it could widen if investors prefer the new ETF structure.

ARKK, managed by ARK Invest, is known for its focus on innovative and disruptive technologies, including cryptocurrencies. If the SEC is moving towards approving a Bitcoin ETF, ARKK could be seen as a potential beneficiary due to its investment style and interest in the crypto space, possibly leading to increased investor interest and a positive impact on its stock price.

BlackRock (BLK) is one of the world's largest asset managers and has shown interest in digital assets. If the SEC is in advanced talks regarding a Bitcoin ETF, BlackRock could be in a position to capitalize on this new product, which could positively influence their stock as they expand their ETF offerings.