Twitter raised over US$57 million from venture capitalist growth funding, although exact numbers are not publicly disclosed. Twitter's first A round of funding was for an undisclosed amount that is rumored to have been between US$1 million and US$5 million. Its second B round of funding in 2008 was for US$22 million and its third C round of funding in 2009 was for US$35 million from Institutional Venture Partners and Benchmark Capital along with an undisclosed amount from other investors including Union Square Ventures, Spark Capital and Insight Venture Partners. Twitter is backed by Union Square Ventures, Digital Garage, Spark Capital, and Bezos Expeditions.
In May 2008, The Industry Standard remarked that Twitter's long-term viability is limited by a lack of revenue. Twitter board member Todd Chaffee forecast that the company could profit from e-commerce, noting that users may want to buy items directly from Twitter since it already provides product recommendations and promotions.
The company raised US$200 million in new venture capital in December 2010, at a valuation of approximately US$3.7 billion. In March 2011, 35,000 Twitter shares sold for US$34.50 each on Sharespost, an implied valuation of US$7.8 billion. In August, 2010 Twitter announced a "significant" investment lead by Digital Sky Technologies that, at US$800 million, was reported to be the largest venture round in history.
Twitter has been identified as a possible candidate for an initial public offering by 2013.
In December 2011, the Saudi prince Alwaleed bin Talal invested $300 million in Twitter. The company was valued at $8.4 billion at the time.