In an interview with Bloomberg, Grayscale CEO Michael Sonnenshein said Grayscale would consider legal action against the SEC over the conversion of the Grayscale Bitcoin Trust to an ETF if the conversion continues to be denied. Grayscale first applied to convert their trust product to a superior Bitcoin spot ETF product in April 2021, but that application was denied. Since then many other applicants have applied, and all have been denied citing potential for "market manipulation" from the SEC. Currently only a futures ETF product is available.
So far there have been 3 futures products approved, the Proshares Bitcoin Strategy ETF (BITO), Valkyrie Bitcoin Strategy ETF (BTF), and VanEck Bitcoin Strategy ETF (XBTF). Futures and Spot ETFs differ in the asset which they hold. Futures assets hold a "futures contract", which is a contract to trade or buy an asset (such as Bitcoin) at a fixed price at a specified future date. These Futures ETFs roll over these contracts month to month, selling its position before expiration and purchasing new contracts. This can create something called "contango". Contango happens when the futures price is higher than the spot price, and because the futures price inevitably must trend towards the spot price, futures investors can lose money in these scenarios. This can be avoided by investing in the spot price, and thus using a spot ETF (or much more effectively...holding bitcoin). These spot ETFs hold the actual commodity (bitcoin) directly correlating the value of the ETF to the current value of the commodity.
Grayscale has been attempting to convert its trust product to an ETF product for a number of reasons. It would list GBTC on the New York Stock Exchange. It would allow the price of the newly converted ETF to more accurately track the price of Bitcoin, which would help eliminate premiums and discounts. And, it would lower the fees associated with purchasing and holding the ETF.
The SEC is giving investors 240 days to submit comments on their thoughts about approving a spot ETF/converting Grayscales trust product to an ETF. You can find more information through GBTC here.
We would recommend, if you are able to, to hold bitcoin yourself and not through an investment vehicle such as an ETF (and to self custody). But, if for whatever reason, it is your only access to Bitcoin, a Spot ETF would be a better alternative than the current Futures product.