When the Securities and Exchange Commission denied Grayscale its petition for a Bitcoin ETF, that action was “arbitrary and capricious,” an appeals court ruled today. The SEC ruling has been vacated.

Last year, Grayscale applied for the approval for the fund and was denied. An ETF, or exchange-traded fund, is a pooled investment that is tied to a specific set of assets, which might be an index, a sector, a set of commodities, or something else. Grayscale’s is “something else” — Bitcoin. That could let large investors, such as pension funds, invest in Bitcoin.

The SEC has previously approved ETFs that track Bitcoin futures, but not so-called spot ETFs, which directly track Bitcoin price. Grayscale wanted to convert its Bitcoin trust to an ETF, which would let investors trade shares more freely than the closed-end trust currently allows. Because it’s difficult for investors to trade their shares, Grayscale’s trust often trades below the actual price of the Bitcoin it represents. The switch to an ETF would make it easier to create and destroy shares, so that discount would vanish.

The appeals court found that the Grayscale ETF was treated differently than similar products, such as Bitcoin futures ETFs. If the appeals court’s ruling stands, it may open the door for other Bitcoin ETFs. Firms such as BlackRock and Fidelity have applied for their own ETFs. The SEC has 45 days to appeal this ruling.