(Bloomberg) -- Oil investors are cashing out of funds that track prices for the first time in seven months after crude rebounded.

Holders of the three biggest U.S. exchange-traded products that follow oil have withdrawn almost $300 million so far in April, leaving the funds poised for their first monthly outflow since September. West Texas Intermediate climbed to near $54 this month after reaching a six-year low of $43.46 in March.

WTI has risen on speculation a falling number of oil drilling rigs will slow the U.S. production boom. Investors poured more than $5 billion into the U.S. Oil Fund and two other oil ETPs in the past six months, even as prices lost half its value since June.

“Certainly some people very successfully managed to call something close to the bottom and had a $10 run,” said Dave Nadig, chief investment officer of San Francisco-based ETF.com. “You’d expect profit taking. I don’t think anybody is particularly thinking that we are headed back to a $100 oil market.”

A total of $288 million has been withdrawn from the three biggest U.S. oil ETFs this month, according to data compiled by Bloomberg. The U.S. Oil Fund, the biggest oil ETF, saw an outflow of $171.4 million. The fund, which follows WTI prices, rose 0.5% Monday on the New York Stock Exchange, up 9.9% this month. ProShares Ultra Bloomberg Crude Oil and iPath S&P GSCI Crude Oil Total Return Index ETN also had outflows.

LOWER VOLATILITY

“While some investors may have come in and timed the recent rebound perfectly, the flow indicated that the cashing out could also be burned investors cutting their losses, no longer certain that oil will get back to its glory days,” said Eric Balchunas, a Bloomberg Intelligence analyst.

Falling investment this month also came as oil price volatility decreased. The CBOE Crude Oil Volatility Index, which measures oil price fluctuations using options of the U.S. Oil Fund, slipped to 43 on April 10, the lowest since December. The index was 44.3 Monday.

The number of U.S. Oil Fund shares on loan to short sellers was 56 million as of March 31, or about 1.7 times of average daily volume, according to exchange data. That’s up from 52.3 million on March 13.

WTI futures gained 48 cents to $52.39 a barrel in electronic trading on the New York Mercantile Exchange at 12:24 p.m. Singapore time Tuesday. Prices climbed 15% in the previous four weeks, the longest streak of weekly gains since February 2014.

The U.S. oil rig count declined to 760 last week, the lowest level since 2010, according to Baker Hughes Inc. The number of rigs has dropped by more than a half since it peaked in October at 1,609.

Oil production averaged 9.33 million barrels a day in March, according to the Energy Information Administration. That’s the highest monthly level since 1973. Output will peak in April and start to decline in June, according to EIA’s forecasts.

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