Investors pulled more than $1 billion yesterday from the biggest junk-bond ETF, BlackRock's $27.8 billion fund that trades as $HYG. It's the biggest daily withdrawal since February, and one of the bigger ones in the fund's history.

Interestingly, traders also pulled $744 million from $LQD, the popular U.S. investment-grade bond ETF, even though some traders had been treating top-rated credit almost as nearly interchangeable with U.S. Treasuries for much of the year.

This is the first sign of real risk aversion in riskier US credit since June. Junk-debt spreads stayed pretty consistent through recent jitters in big tech, but the threat of no extra fiscal support, paired w/growing political uncertainty, pushed spreads notably wider yesterday