Big-name hedge fund managers, including David Einhorn and Larry Robbins, pitched stock ideas ranging from airplane lessors to biotech companies that are working to extend the human lifespan at the Sohn Investment Conference in New York on Monday.

Greenlight Capital’s Einhorn, who made his name pitching a timely short of Lehman Brothers before the 2008 global financial crisis, announced a long position in airplane leasing company AerCap Holdings and a short position in rail car leasing company GATX Cor.p, which he said has higher maintenance costs and less visibility into future revenues but trades at higher multiples than AerCap.

“We think the market has this wrong,” he said.

Einhorn, who has been a prominent critic of electric vehicle pioneer Tesla Inc, started his 15-minute presentation by silently showing several slides of Tesla Chief Executive Elon Musk and his bullish pronouncements for the company before calling it “a lot of horseshit.”

Tesla did not immediately respond to a request for comment.

Larry Robbins of Glenview Capital LLC, meanwhile, reiterated his long positions in HMOs such as Cigna Corp, whose shares have fallen on concerns about progressive Democratic candidates endorsing so-called “Medicare for all” plans ahead of the 2020 elections. He also remained bullish on hospitals overall.

“Hospitals are not under attack, hospitals are a wonderful place to invest,” he said.

The wide range of investment ideas reflected the challenge for portfolio managers to find undervalued assets at a time when global stock markets are near record highs.

The U.S. benchmark S&P 500 hit two record highs last week and is up 17 percent year-to-date, thanks in large part to an expanding economy and the Federal Reserve’s surprising decision in January to pause its interest rate hikes.

The average hedge fund was up 5.7 percent in the first quarter, the best start to a year since 2006, according to industry publication Hedge Fund Research.

Not all the investment ideas were bullish. Ryan Heslop, portfolio manager of Firefly Value Partners LP, announced a short position in rural hospital operator Community Health Systems Inc, which he said will likely go bankrupt over the next few years as its revenue per hospital bed shrinks and its debt costs increase.

The company’s “pile of debt and the declining profitability of hospitals make it almost certain that this patient will die,” he said.

Community Health did not immediately reply to a request for comment.

Spencer Glendon, founder of Probable Futures, said increasing global temperatures and more severe storms due to the effects of climate change will undercut the economy of Florida and its housing market.

As a result, he is short Floridian mortgage-backed securities, Florida municipal bonds, and banks with high exposures to the state.

"When the Florida housing market falters, everything will go with it ... they are utterly dependent on real estate," he said.

Laura Deming, managing director of the Longevity Fund, announced positions in biotech companies such as Precision BioSciences Inc, ALX Oncology and Navitor Pharmaceuticals that are working to extend the human lifespan by targeting specific cells and biological processes.

“Shouldn’t we get to choose in some way what number we get to live to?” she said.