US spot Bitcoin ETFs lost a net $82.39 million on Friday, October 16, with BlackRock reportedly pulling out the most. October withdrawals now sit near $1 billion. Let me explain why $BTC watchers track this. An ETF lets people gain exposure through a normal brokerage account, so flows can show how traditional investors feel. Outflows suggest caution, while inflows suggest appetite. One day is a small sample, though. I look at weekly totals before I draw any conclusion, and I compare them with price action so I do not read too much into a single print.