Ah true not all ETFs just most by institutions and BTC under management I would venture.
Discussion
I looked it up and it’s actually Fidelity that has its own custody and Van Eck uses Gemini. The rest, Coinbase. So that’s a risk one might address by custody diversification across the three.
Yeah I hadn't really thought of that buying across all 3. Could also self custody but that kinda defeats the purpose of an ETF for those buyers I suppose.