You certainly make a good point, but in defense of the Buffet Indicator, perhaps the tendency for private companies to go public and vice versa also depends on

You certainly make a good point, but in defense of the Buffet Indicator, perhaps the tendency for private companies to go public and vice versa also depends on economic conditions. Being a public company can be a costly and burdensome proposition, so unless there's a clear increase in ROI in terms of access to capital and shareholder liquidity, there's no real incentive for a profitable private firm to go public. So if a lot of private companies are going public, then that could also be an indicator that the public markets are overheated and something is fundamentally out of balance.