Nervous markets are churning at fastest rate since 2008

Once the hallmark of this bull run, complacency has made way for angst.

From junk bonds to emergingmarket stocks, market turnover is through the roof, reaching multi-year highs. Within the S&P 500 Index, investors traded more than $2.9 trillion worth of shares in each of the past two quarters, a feat last achieved in early 2008.

Burgeoning uncertainty — from monetary policy and protectionism, to cracks in the synchronized growth story — has spurred elevated trading across assets.

“Market turnover tends to be high when uncertainty is high, as institutional investors tend to reshuffle their portfolios,” JPMorgan Chase & Co. strategists including Nikolaos Panigirtzoglou wrote in a note last month. “Negative growth revisions coupled with political and policy risks including the Italian crisis and trade war risks are creating a lot more uncertainty this year relative to last year.”

It’s a similar story for developing-nation assets at the mercy of a strengthening U.S. dollar and trade tensions. Volume on the MSCI Emerging Market index reached $1.9 trillion in the three months through June, the most since 1998 when a wave of currency devaluations and defaults ripped through emerging economies from Thailand to Russia.

Churn on the most popular exchange-traded funds has similarly surged. ETF trading typically picks up during major macro events, as investors hedge and move positions with broad exposures. The iShares high yield credit ETF saw record quarterly turnover this year, while the largest stock ETFs had the most tumultuous first half in as much as a decade.