Sigma Partners is a venture capital firm specializing in investments in early stage companies. The firm typically invests in the software, communications, semiconductors, storage, mobile computing, electronics, infrastructure, and Internet services sectors. It primarily invests in companies based in the United States. The firm seeks to invest between $2 million and $8 million and also takes a board seat in its portfolio companies. Sigma Partners was founded in 1984 and is based in Boston, Massachusetts. It has additional offices in Menlo Park, California and San Ramon, California.