Citron Research editor and notorious short seller Andrew Left discussed one of his latest stock ideas during an appearance on Benzinga’s PreMarket Prep show this week.

COMPASS Pathways PLC (NASDAQ:CMPS) shares may have ended Tuesday's session down 3.76%, but Left has a bullish thesis for the stock.  

“They are the first ones using psilocybin, what’s in the magic mushrooms, for FDA approval for mental health purposes. They just went public. It’s one of those big concept stocks,” he said. 

Left said the trading action in Tesla Inc (NASDAQ:TSLA) and Beyond Meat Inc (NASDAQ:BYND) is a clear demonstration that the market is hungry for story stocks.

See Also: Mind Medicine CEO Calls Compass IPO A 'Clear Bellwether' For Psychedelic Space

Paypal Holdings Inc (NASDAQ:PYPL) co-founder Peter Thiel is a major investor in Compass Pathways, and the company has a top-notch board of directors.

Compass is targeting psilocybin's potential to help people with mental health issues such as depression, anxiety and PTSD. Compass’ leading drug candidate COMP360 is in Phase 2 testing, and the company said it could be ready to begin Phase 3 testing as soon as 2022 if the Phase 2 data is promising.

The U.K.-based Compass priced its IPO at $17 per share on Sept. 18. Shares have since traded as high as $45 and closed Tuesday's session at $35.61. 

Compass shares are likely even higher risk than the typical early-stage biotech stock given that psilocybin is a Schedule I-listed controlled substance in the U.S. Left said he's undeterred.

“The market loves a good concept stock,” he said.

Watch to the full interview with Andrew Left in the clip below, or listen to the podcast here