In a report CBInsights analyzed 1100 startups (that raised seed rounds in 2008-2010) to answer exactly that question. Post seed funding 67% startups stall at some point, fail to raise or exit (unless they become self sustaining but unattractive for investors).
Bottomline – 50% do not get to Round 2. 90% are gone by Round 3.
48% managed to raise 2nd round. 63% of these got to second follow on/3rd round (Series B). 15% got to 4th round (Series C). Average time to raise is 20 months except in the 6th round which is taking 5 months due to investor eagerness.
Median seed was $350K while average was $670K. The 6th follow on round mean was $40M while average was $120M.
Odds of becoming a Unicorn is 1%. 12 companies reached that status in 2017-18 including over hyped companies like Uber, AirBnB, Slack, Stripe, and Docker.
13 companies existed for over $500Mn including – Instagram, Zendesk and Twilio.
30% seed funded companies exited through an IPO or M&A.
Link to report : Venture Capital Funnel Shows Odds Of Becoming A Unicorn Are About 1%. It has the analysis of 2017 and 2015 as well. Marginal change YOY in % terms in each stage. Take a look.