Mark Zuckerberg's mortgage rate 1.05% While almost all lending rates have reached record lows this year, the borrowing costs available to high-net-worth individuals like Zuckerberg are even lower if the person is willing to bear the risk of monthly interest rate adjustments, said Greg McBride, senior financial analyst with Bankrate Inc., which tracks interest rates. IPO's effect"There was a huge run-up before the Facebook IPO and it cooled off after the Facebook fizzle," Ken DeLeon, a Palo Alto real estate broker, said about local home prices. First Republic Bank, which provided Zuckerberg's mortgage, doesn't comment on specific loans or clients, said Greg Berardi, a spokesman for the San Francisco company. "First Republic, like most banks, prices its credit products based on the strength and totality of the entire client relationship," he said in an e-mail. The bank's high-net-worth customers include Stephen Ross, the chairman of developer Related Cos.; Peter Thiel, the chairman of hedge fund Clarium Capital LLC and an early Facebook investor; and former New York Police Chief William Bratton, the current chairman of Kroll Inc., according to First Republic's website. Financing for wealthyBanks like to provide home loans to high-net-worth clients because they can pay off the loan quickly, if needed, and are better credit risks, said Sandi Bragar, director of planning at San Francisco wealth manager Aspiriant. Wealthy individuals often choose to finance a home purchase rather than pay cash because of the overall low cost of mortgage debt and the additional access to liquidity, Kricena said.