Hundreds of millions of dollars has poured into master limited partnerships in the last month. Very little of it is coming back out.

Even with this week’s mini-rally in the securities, an exchange-traded fund tracking the Alerian MLP Infrastructure Index has plunged 22 percent since the start of November while simultaneously sucking in more than half a billion dollars of inflows. In other words, the security has received more money from investors than any time in almost four years while the underlying index is in the midst of its second-worst monthly plunge since 2008.

The ETF’s market capitalization stands at $6.6 billion now compared with $7.6 billion then -- $574 million of fresh cash notwithstanding.

Things are getting worse, not better, in a space that has been dishing out servings of pain for more than a year. This in a group of securities whose supposed attraction is in its resilience to energy market fluctuations. MLPs are investment vehicles structured to operate pipelines without paying federal income tax by passing earnings to investors.

“Clearly people want to be in at the bottom, and they’re trying to pick exactly when,” said Randy Warren, who manages more than $100 million at Exton, Pennsylvania-based Warren Financial Service & Associates Inc. “That’s pretty dangerous and difficult to pull off. You have to be careful -- the energy space is deadly right now.”

Shares in the ETF tumbled to a record on Monday as crude oil slumped to a six-year low and speculation mounted that MLPs will have to start cutting dividends in order to preserve their credit ratings. The ETF lost 42 percent in 2015 through Dec. 7. It slipped 4.1 percent at 9:47 a.m. in New York.

As money managers chase an oil recovery that hasn’t yet come, strategists across Wall Street are stoking optimism. Just this week JPMorgan Chase & Co. boosted its rating on U.S. energy companies to a buy and Barclays Plc upgraded global oil producers. The ETF yesterday had its biggest one-day gain since its inception in August 2010.

Investors should temper their expectations, according to Warren.

False bottoms have occurred in the past. Clients started moving money into the MLP-tracking ETF last month as the Alerian MLP Infrastructure gauge surged 11 percent over a five-day span ending Nov. 3. The fund took in $327 million in the next three weeks just in time for the rally to reverse completely. The ETF ended up absorbing $354 million in November, its biggest monthly inflow since January 2012.

While MLPs may be struggling, investing in them still represents a superior way to pick a market bottom in oil when compared with instruments that don’t provide cash payments, according to Warren.

“The dividend piece is a good way to play these things in the future,” he said. “You’re getting paid while you’re waiting.”