Greenlight Capital’s David Einhorn posted one of his best years ever with an outstanding return north of 30%, thanks in part to his short position in a slew of innovative technology stocks like those touted by growth investor Cathie Wood. The star hedge fund manager said his fund rallied 36.6% in 2022, compared to a 19.4% loss for the S & P 500. Einhorn also said he is still short some ‘bubble’ names. “2022 was an exceptionally good year,” Einhorn said in the new investor letter obtained by CNBC. “In many ways it was our best ever and is most comparable to 2001, the year after the last technology bubble popped.” Driving the stellar performance was a successful bet against what seemed to be the constituents of Wood’s flagship ARK Innovation ETF (ARKK) . “In early 2021, we also identified an actively-managed ETF of so called ‘innovation’ stocks that appeared to us to have significantly similar characteristics to our bubble names,” stated the letter. The investor revealed that he shorted a basket made up of the unnamed ETF in February 2021 with 9% of his capital. The basket has fallen 76% from his first entry, and the cumulative positive impact on his returns has been 6.4% of capital, Einhorn said. While Einhorn didn’t mention ‘ARKK’ by name in the letter, it very likely is a reference to Wood’s flagship fund which is the most notable active ETF focused on innovation and declined 66% in 2022. Currently, the ARK fund holds 29 names with its components including Invitae , Coinbase , Twilio , Unity Software , Roku , Teladoc and Tesla have dropped over 60% from their 52-week high. Greenlight didn’t immediately return to CNBC’s request to confirm the ETF it referred to. ARKK 1Y mountain ARK Innovation ETF’s 1-year sell-off Einhorn said he created another “bubble” basket with 31 names totaling 6.5% of capital in January of last year. He defines a bubble stock as one that could fall at least 80% and still not appear cheap after looking at the company’s financials and valuations. Einhorn said this bubble basket remained in the portfolio but he has covered some positions. All but one of these stocks are down through the end of 2022 from his entry with 24 of them down more than 70%, the manager said. “This was a year where many of those who rode the bubble suffered losses, raising the question as to whether the risks were worth taking,” Einhorn said. On the long side, Greenlight’s significant winners in 2022 included Atlas Air Worldwide , CONSOL Energy, Teck Resources and merger arb play Twitter. Einhorn also revealed that he established a new medium-sized long position in hospitals and ambulatory surgery centers operator Tenet Healthcare during the fourth quarter. He said a Covid-driven sell-off had created an attritive opportunity to participate in the company’s transformation. — CNBC’s Michael Bloom contributed reporting