Brad Feld (born December 1, 1965) is an American entrepreneur, author, blogger, and venture capitalist at Foundry Group in Boulder, Colorado, a firm he started with partners Seth Levine, Ryan McIntyre, and Jason Mendelson. Feld began financing technology startups in the early 1990s, first as an angel and later an institutional investor. Feld was an early investor in Harmonix, Zynga, MakerBot, and Fitbit.