Venrock

With a zest for investing and a whole lotta moolah at its disposal, Venrock Associates invests primarily in early-stage technology, health care, digital media, and energy companies. The firm has invested more than $2 billion in some 430 companies since it was founded in 1969 as the venture capital arm of the Rockefeller family. About 125 of those investments resulted in IPOs, and another 125 were exited via a merger or acquisition. Its notable past investments include Apple, Internet advertising provider DoubleClick, and Intel. Venrock's current portfolio consists of more than 100 firms.