What flows in must flow out, at least when it comes to investment products. And so it goes with U.S.-listed exchange-traded funds, which experienced nearly $12 billion in outflows in June, according to data from IndexUniverse.

The San Francisco-based ETF research company said the pain was spread across nearly every asset class in what appears to be a record for monthly outflows. That left the U.S. ETF industry with about $1.44 trillion in assets as of the end of June, or roughly 5 percent less than what it had at the start of the month.

Investors began their retreat from ETFs in late May after Federal Reserve Chairman Ben Bernanke rattled the markets when he said the central bank could begin tapering down its unprecedented economic stimulus program later this year. The iShares MSCI Emerging Markets (EEM) fund saw the most outflows last month at $3.84 billion, followed by the SPDR S&P 500 (SPY) and the iShares iBoxx $ Investment Grade Corporate Bond (LQD) funds. The remaining top, or bottom five were the SPDR Gold (GLD) and iShares Barclays TIPS Bond (TIP) funds.

International equity, U.S. and international fixed income, and commodities saw the biggest outflows among categories. Meanwhile, U.S. equity ETFs raked in nearly $5 billion in inflows as investors sought safety from those markets that cratered.

According to IndexUniverse, this year’s first half saw total inflows into U.S. ETFs of a little more than $73 billion, which is $3 billion less than the year-earlier period. Some ETF industry watchers thought 2013 would top last year’s record inflows of $188 billion. But after a rough June for ETFs and prospects for more volatility as the Fed possibly starts to unwind its quantitative easing program, that might not be happening.