The rules aren't clear. I wonder if wash sales apply since they don't on the underlying btc. Here are some references. Have you read the opposite? Interested in your source and if I if it's different as an ETF.

https://privatebank.jpmorgan.com/nam/en/insights/wealth-planning/for-your-year-end-tax-planning-beware-the-wash-sale-rule#:~:text=The%20wash%20sale%20rule%20does,assets%20(such%20as%20cryptocurrency).

The wash sale rule does not currently apply to direct investment in assets other than stock or securities, including commodities (such as allocated gold), currencies or digital assets (such as cryptocurrency).