Einhorn è anche uno dei principali azionisti e Presidente di una Società di Riassicurazione basata nelle isole Cayman la Greenlight Capital Re Ltd.

 Sposato dal 1993 con Cheryl Beth Strauss che gli ha dato 3 figli, vivono nella contea di Westchester nello stato di New York.

 Appassionato di baseball, David fa parte dei CdA di più associazioni benefiche ed è conosciuto per le generose donazioni delle sue vincite ottenute ai Campionati di Poker di cui è professionista ai massimi livelli.

 Anche se è più noto come giocatore di poker, Einhorn è anche un abile bridgista.

David Einhorn (born November 20, 1968), an American hedge fund manager, is the founder and president of Greenlight Capital, a "long-short value-oriented hedge fund". He started Greenlight Capital in 1996 with $900,000. Greenlight has generated about a 20% annualized return for investors. Einhorn is also the Chairman of Greenlight Capital Re, Ltd, a Cayman Islands-based reinsurance company and is a major shareholder.

Einhorn has received extensive coverage in the financial press for short selling Allied Capital, Lehman Brothers and Green Mountain Coffee Roasters stock. He is also a critic of current investment-banking practices, saying they are biased to maximize employee compensation. He cites a statistic that investment banks pay out 50 percent of revenues as compensation, and higher leverage means more revenues, making this model inherently risky.

Einhorn was a director at New Century Financial Corp., a major subprime mortgage lender, between March 2006 and March 2007. Greenlight Capital held 6.3% of the company's stock at the time he resigned from the board. A class action lawsuit was brought against 13 former directors and senior management of New Century. The lawsuit did not allege any specific wrongdoing by Einhorn and was settled in 2010 without any finding of liability on Einhorn's part. The settlement was funded by more than $90 million in payments from New Century's D&O carriers and personal payments by certain members of senior management.

He is also a founding Master Player of the Portfolios with Purpose virtual stock trading contest.

Although more famous as a poker player, David Einhorn is also an accomplished tournament bridge player.

Einhorn absolvierte bis 1987 die Nicolet High School in Glendale (Wisconsin). Er erhielt 1991 am College of Arts and Sciences der Cornell University den BA in Government mit der Auszeichnung summa cum laude. Einhorn war Mitglied der Studentenverbindung Sigma Alpha Epsilon an der Cornell University.
1996 gründete Einhorn Greenlight Capital, einen Hedgefonds, der seitdem etwa 20 % Rendite jährlich erwirtschaftete (Stand 2012). Er ist Präsident von Greenlight Capital und Vorsitzender von Greenlight Capital Re, Ltd.
Einhorn verdient laut Medienberichten derzeit etwa 80 Millionen US-Dollar pro Jahr und besitzt ein geschätztes Vermögen von 1,1 Milliarden US-Dollar (Stand 2012).

Obwohl mehr berühmt als Pokerspieler, ist David Einhorn auch ein versierter Turnier Bridge-Spieler.