Volume in S&P 500 stocks was 25% lighter than the average during the last 30 days, the first time this year where trading fell at least 15% two sessions in a row. The slide in volume came just ahead of Friday’s quadruple witching, during which options and futures on indexes and equities are scheduled to expire.

“The story has been and remains that with such powerful cross-currents facing the market we are going to have periods of positivity and even exuberance, and we’re going to have moments of disappointment,” said Lauren Goodwin, economist and multi-asset portfolio strategist at New York Life Investments. “It’s just endemic of the economic, political, earnings, health, everything environment just being so uncertain.”

Elsewhere, the Stoxx Europe 600 declined. The pound held onto losses and gilt yields rose after the Bank of England expanded its quantitative easing program.

The picture for global markets remains complex as investors mull reports on China battling its worst outbreak since Wuhan, and Israel pausing further reopening of the economy after a rise in cases. That’s competing with some positive news on the economic front, as well as a flood of promised stimulus measures.

“The markets are fragile right now and I think a lot of investors see how quick the markets have recovered — equity market in particular,” said Chris Gaffney, president of world markets at TIAA Bank. “Everyone is starting to feel that maybe we’re ahead of ourselves.”

These are some of the main moves in markets: