I would assume this headline is "of all companies for which founding papers are filed in America". That seems a poor statistic to use when 65% of Americans try to start a business at some point.

A more meaningful number might be % chance among companies who received venture funding. A funding event represents a concrete shift in probability of success.

Does anyone commenting here know the probability of, say, a $10M, $100M, and $1B exit after a Silicon Valley funding event (funding from recognized VC)?