Internet reports that the U.S. Securities and Exchange Commission is considering a proposal to change BlackRock's spot bitcoin exchange-traded funds to allow physical redemption. In a document released Thursday acknowledging the proposal, the SEC required comments to be submitted within 21 days of the document's publication in the Federal Register. The agency could then decide to approve, veto or "initiate litigation proceedings," the document said. According to Form 19b-4 documents, Nasdaq last month issued a revised rules document on behalf of BlackRock to allow redemption and physical creation of iShares Bitcoin trusts.