Ask HN: Expected ROI of a random investment strategy in startups?

Even formulating a precise definition of those things is tough, but I'm curious if there has been any good analysis on what kind of a baseline ROI you would expect a random strategy to net if you are picking from some restricted domain like early stage tech startups of a certain type. I understand its not a precise analogue to the stock market, but it would be interesting to see if you could get a gist of an answer.