Investors who took a hit last year when dozens of U.S. shale producers filed for bankruptcy are already making big new bets on the industry’s resurgence.

In the first quarter, private equity funds raised $19.8 billion for energy ventures – nearly three times the total in the same period last year, according to financial data provider Preqin.

The quickening pace of investments from private equity, along with hedge funds and investment banks, comes even as the recovery in oil prices CLc1 from an 8-year low has stalled at just over $50 per barrel amid a stubborn global supply glut.

The shale sector has become increasingly attractive to investors not because of rising oil prices, but rather because producers have achieved startling cost reductions – slashing up to half the cost of pumping a barrel in the past two years. Investors also believe the glut will dissipate as demand for oil steadily rises, according to Reuters.

That gives financiers confidence that they can squeeze increasing returns from shale fields – without price gains – as technology continues to cut costs. So they are backing shale-oil veterans and assembling companies that can quickly start pumping.

“Shale funders look at the economics today and see a lot of projects that work in the $40 to $55 range” per barrel of oil, said Howard Newman, head of private equity fund Pine Brook Road Partners, which last month committed to invest $300 million in startup Admiral Permian Resources LLC to drill in West Texas.

Data on investments by hedge funds and other nonpublic investment firms is scant, but the rush of new private equity money indicates broader enthusiasm in shale plays.