For investors in shale drilling, the party's over

MENTONE, TX - FEBRUARY 05: The shadows of workers with Apache Corp. are viewed at the Patterson 298 natural gas fueled drilling rig on land in the Permian Basin on February 5, 2015 in Mentone, Texas.The rig, which is only 21 days old, is the first drilling rig in Texas that is 100-percent fueled by natural gas. As crude oil prices have fallen nearly 60 percent globally, many American communities that became dependent on oil revenue are preparing for hard times. Texas, which benefited from hydraulic fracturing and the shale drilling revolution, tripled its production of oil in the last five years. The Texan economy saw hundreds of billions of dollars come into the state before the global plunge in prices. Across the state drilling budgets are being slashed and companies are notifying workers of upcoming layoffs. According to federal labor statistics, around 300,000 people work in the Texas oil and gas industry, 50 percent more than four years ago. (Photo by Spencer Platt/Getty Images) less MENTONE, TX - FEBRUARY 05: The shadows of workers with Apache Corp. are viewed at the Patterson 298 natural gas fueled drilling rig on land in the Permian Basin on February 5, 2015 in Mentone, Texas.The rig, ... more Photo: Spencer Platt, Staff Photo: Spencer Platt, Staff Image 1 of / 5 Caption Close For investors in shale drilling, the party's over 1 / 5 Back to Gallery

Wall Street appears to have lost its taste for the resurgent U.S. shale industry as oil prices tumble and energy share prices fall.

Oil companies have only raised $3 million this month through selling new shares to investors, a dramatic drop in the public equity offerings that have helped fuel the return of drilling rigs across the nation this year.

It's a stark shift in investor sentiment after last month, when producers like Kosmos Energy and RSP Permian collected a combined $1 billion from stock-market investors. That was before U.S. oil prices took a month-long tumble of around 20 percent to $43.15 a barrel on Friday.

Some investor groups have said "they had little-to-no interest in providing a second lifeline to the industry," Houston investment bank Tudor, Pickering, Holt & Co. said in a note to clients on Friday.

"It's like you're having a party, and it's awesome, and then the parents come home, and the party's done," said David Pursell, head of macro research at Tudor Pickering. "There's no appetite to fund further growth. Oil prices went from the mid-$50s to the low $40s. It's a big change and it happened quickly."

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The once-vibrant public equity markets had poured $8 billion into U.S. shale drillers in the three months after OPEC announced it would cut oil production, and the number of active U.S. drilling rigs boring has more than doubled since last summer.

But the in wake of the recent slump in oil prices, the oil companies that raised billions of dollars this year have seen their shares drop by 22 percent this year. If investors keep pulling back, the surge in drilling could slow sharply, Pursell said. And why wouldn't they? Other industries are performing much better than energy.

"The Dow's at record levels and energy isn't working," Pursell said. "It's just maximum indifference. You have to get the oil price up for investors to care."

In the note, Tudor Pickering analysts said some oil companies "will need to change course on capital plans sooner rather than later if crude continues to drift lower."

Related: Falling oil prices could drag on Houston's economy, again