Twitter has closed its latest round of funding, securing a reported $200 million at a whopping $3.7 billion valuation.
According to All Things Digital, the lead investor in the round is Kleiner Perkins Caufield & Byers (KPCB). Twitter confirmed a "significant new round of funding" on its blog.
With the funding, Twitter has now raised an estimated $360 million. The company's last major round came in September 2009, when it closed $100 million in funding at a valuation of around $1 billion.
At that time, Twitter was a quickly growing social networking site without much of a business model to speak of. Since then, the company has introduced a variety of revenue streams, most prominently its Promoted Tweets and Trends products, which appear to be on their way to wider rollout in the new year.
The company has also seen some significant personnel changes, with former COO Dick Costolo replacing Evan Williams as CEO back in October. Around that time, Twitter reported that it had 300 employees in total.
Although one of Silicon Valley's most prominent venture capital firms, the deal represents the first investment KPCB has made in Twitter. KPCB is also one of the lead investors in the Facebook-led sFund and previously launched the iFund for investing in iOS apps.