Read? Investment Portfolio Draw-down Across Market Cycles
Cash is rotting due to inflation so the opportunity cost of holding is to beat inflation rate. Uncle8888 is assuming 2.5% yearly inflation rate.
His opportunity cost for rotting cash in his war chest is ....
the number doesn't look too scary to beat it. To generate at least 68% ROC on war chest by 2030 i.e. another 12 years for the next Big Bear! ......