Spectrum Equity Investors-backed Ancestry.com (NASDAQ: ACOM) has filed for a secondary public offering of 3.75 million shares of common stock. Spectrum is selling about 3.5 million of the shares. The underwriting is being led by Morgan Stanley and BofA Merrill Lynch. Ancestry.com also announced that it intends to repurchase about $25 million of its common stock directly from the selling stockholders in a private, non-underwritten transaction. The company's stock has more than doubled since its IPO in November 2009.