“Work chat’s runaway train” raises $200M. Business messaging startup Slack announced on Friday afternoon that it’s raised $200M in new funding at a $3.8B post-money valuation. The round, which was led by Thrive Capital, with participation by GGV, Comcast Ventures and existing investors, brings the three-year-old company’s total funding to a whopping $540M. In the year since Slack was last valued at $2.8B, the company is reporting 3.5x user growth. Another $600M for Mithril Capital Management. Just one week after Founders Fund closed its sixth fund with $1.3B, Peter Thiel’s late-stage fund Mithril Capital Management is out raising its second fund, according to an SEC filing. The target size is $600M, but according to TechCrunch’s sources, the fund is already oversubscribed and may hit $1B before final close. How to build a weatherproof company: For any startups looking for a “quick exit,” Lars Dalgaard of Andreessen Horowitz explains why “successful companies are bought, not sold.” His five tips for scaling without shortcuts: 1) learn how to learn fast, 2) build a sustainable culture, 3) leverage your board of directors, 4) find the right meeting cadence, and 5) kill the monsters of the mind. New interactive data visualizations with the most active investors. Check out the detail-rich CrunchBase Unicorn Leaderboard. | 
