William R. Hambrecht (born 1935) is an American investment banker and chairman of WR Hambrecht + Co which he founded in 1998. He helped persuade Google to use an Internet-based auction for their initial public offering (IPO) in 2004, instead of a more traditional method using banks and other financial companies to find buyers. He is credited with popularizing this "OpenIPO" model, using Dutch auctions to allow anyone, not just investing insiders, to buy stock in an IPO, potentially raising more money for startups. Some of the companies he has helped have an IPO like this include Overstock.com, , Andover.net and Salon.com.