Twitter, the fashionable microblogging service, is set to close a round of financing of around $100 million that values the three-and-a-half-year-old start-up at $1 billion, according to a person briefed on the company’s plans.
The investors include Insight Venture Partners, a New York venture capital firm, T. Rowe Price, the mutual fund company, and the current Twitter backers Spark Capital and Institutional Venture Partners.