Two securities tied to stock volatility that normally trade tens of millions of shares a day were repeatedly halted Tuesday by exchange circuit breakers after experiencing unusual swings.

The iPath S&P 500 VIX Short-Term Futures exchange-traded note and the ProShares Ultra VIX Short-Term Futures fund set off nine or more halts each starting at about 10:45 a.m. New York time after swinging up and down. A notice on the website of NYSE Arca, one of the biggest U.S. trading venues, said it was investigating a quoting issue that had left some stocks unavailable.

A subsequent notice on the Arca website said systems were working normally again as of 12:19 p.m.

Both securities give investors ways to bet on equity turbulence with returns tied to gauges of U.S. stock volatility such as the Chicago Board Options Exchange Volatility Index. U.S. exchange rules pause trading in stocks when offers to buy or sell them move outside a preset range.

Eric Ryan, a spokesman for the New York Stock Exchange, said he had no immediate comment on the halts.