Concerns about rising oil prices and an end to the stock market rally once quantitative easing ends has caused 40% of hedge fund managers to be bearish on U.S. equities, up from 26% in January, according to the TrimTabs/BarclayHedge Survey of Hedge Fund Managers. And only 26% are bullish, down from 37%.

Furthermore, 37% are bearish on the 10-year Treasury note, and only 15% are bullish.

“Bullish sentiment less bearish sentiment is negative for the first time since November,” said Sol Waksman, founder and president of BarclayHedge. “Increased caution might owe in part to excellent recent performance. Our Hedge Fund Index has posted a positive return for six straight months.

Meanwhile, 18% of managers aim to increase leverage in the near term, and 15% plan to decrease leverage.

“Managers aim to lever up even though they are bearish on both bonds and stocks,” said Vincent Deluard, executive vice president at TrimTabs. “Why? They sill have a large incentive to gamble with borrowed money because short rates round to nil. If one of the Fed’s goals was to ignite speculation and greed, then it has succeeded famously.”

In addition, 52% of hedge fund managers believe the stock market has rallied because of QE2, and 35% think that its end in June will cause the rally to stall. In addition, 24% believe it is more likely that oil will hit $150 a barrel than the S&P 500 will reach 1,600.