[Wilbur Ross, Chairman and CEO of WL Ross and Co., speaks at the Japan Society, Thursday, Nov. 17, 2011 in New York.]AP Photo/Mark Lennihan On Wednesday, President-elect Trump tapped billionaire financier Wilbur Ross as his commerce secretary. The 79-year-old was a senior policy adviser to Trump during his campaign. He amassed his estimated $2.9 billion wealth working first at investment bank Rothschild Inc. before starting his own investment firm, WL Ross & Co. It's that Wall Street background which reportedly earned him membership into secret Wall Street fraternity Kappa Beta Phi. While the invitation-only fraternity is secret, there is a little first-hand information about Ross' membership in Kevin Roose's book "Young Money" which includes a chapter on Kappa Beta Phi and its 80th induction dinner in 2012. Roose adapted a portion of his book for New York Magazine, recounting how he snuck into the party and was eventually caught and thrown out. The excerpt details Ross' welcoming statements at the dinner. Roose wrote: "It was January 2012, and Ross, wearing a tuxedo and purple velvet moccasins embroidered with the fraternity’s Greek letters, was standing at the dais of the St. Regis Hotel ballroom, welcoming a crowd of two hundred wealthy and famous Wall Street figures to the Kappa Beta Phi dinner. Ross, the leader (or 'Grand Swipe') of the fraternity, was preparing to invite 21 new members — 'neophytes,' as the group called them — to join its exclusive ranks." Kappa Beta Phi has existed since before the 1929 stock market crash, and includes some of the biggest names on the Street, Julia LaRoche reported for Business Insider. Those names reportedly include former New York City mayor Michael Bloomberg, former head of Citigroup's wealth management Sallie Krawcheck, and Jon Corzine, a former New Jersey governor and CEO of now-bankrupt brokerage firm MF Global. Largely an honorific society, members meet annually at the St. Regis Hotel for their black-tie dinner to induct new members. Ross has never confirmed his membership, but in Roose's book, the author recounts how intense the situation became when members of the fraternity realized he was a reporter: "A number of prominent Kappas had rushed over to our table. Before the situation could escalate dangerously, a bond investor and former Grand Swipe named Alexandra Lebenthal stepped in between us. Wilbur Ross quickly followed, and the two of them led me out into the lobby, past a throng of Wall Street tycoons, some of whom seemed to be hyperventilating." NOW WATCH: Here’s the difference between a button-up and a button-down shirt