The U.S. Securities and Exchange Commission (SEC) has opened the floor for public input regarding a Nasdaq proposal, which seeks to enable options trading on BlackRock’s (NYSE: BLK) spot Bitcoin (CRYPTO: BTC) ETF. The public comment period, set to last for 21 days, was announced through a filing posted Friday. According to the filing, “The Exchange proposes to amend Options 4, Section 3, Criteria for Underlying Securities, to allow the Exchange to list and trade options on iShares Bitcoin Trust (the ‘Trust’) as a Unit deemed appropriate for options trading on the Exchange.” Bloomberg Intellige…