Which custodian holds each ETF's bitcoin, and how concentrated is the custody layer?

Shares in a brokerage, bitcoin at a custodian. Most funds share one custodian; see the concentration data. It depends on what the holding has to survive: a single point of failure can be excellent at everything else and still lose everything at once, so read that column first, then the fees against your size.

Facts are from each provider's own documents and public filings with the date the record was last checked; "n/s" means not stated by the provider. Scores are Proof of Custody's judgement on the published methodology. Coverage is selected, not exhaustive; absence is not evidence of safety. As data: /data/matrix.json. Dispute a cell through corrections.