insight-venture-partnersWho’s responsible for boosting Twitter’s valuation to around $1 billion?

It looks like East Coast money. New York-based Insight Venture Partners is the new firm backing the fast-growing microblogging network, according to TechCrunch. With more than $3 billion, Insight is a late-stage, private equity buyout fund, not one that would have come in during earlier rounds of financing.

The firm invested in Photobucket, which sold to News Corp. for $300 million in 2007. It was a controversial sale at the time, as some of the firm’s employees banked 15 times their original investment while Insight’s limited partners like pension funds and foundations made nothing, according to The Wall Street Journal. Insight said a smaller VC-sized round of a few million dollars was lower than its minimum requirement for the firm. Insight did not immediately return calls for comment about the Twitter investment.