When David Einhorn speaks, people listen. Sometimes even before he speaks, as in the case of Lehman Brothers this week.

The boy-wunderkind founder of Greenlight Capital, whose harsh opinions of Allied Capital and other short investments have thrust him into a small pantheon of hedge fund traders whose utterances move stocks, spoke Wednesday afternoon to a well-heeled crowd of 1,000 or so investors.

But even before he spoke, Lehman stock sunk 5 percent on rumors that he would eviscerate the bank.

Now, Einhorn had previously disclosed that he was short Lehman, so it was plausible that he would discuss it that day, which he did. And Lehman’s alleged issues aren’t exactly news. Furthermore, there were several pessimistic analyst reports out that day.

But Einhorn’s speech raises the question of whether a new trade has emerged on Wall Street called “Beat the Short.”

In this case the game was complicated by a embargo on release of information from Einhorn’s speech for almost a day. The embargo, introduced by the conference organizers, meant that those attending the event got the benefit of Einhorn’s wisdom well before Reuters and other news organizations could report it to the wider market.

We’ll see what happens before uber-shortseller Jim Chanos speaks at the Securities Industry and Financial Markets Association meeting on June 16 in New York. His recent targets have included some cable companies, student lenders and infrastructure companies.