That's a different definition of efficient than efficient-market theory. The theory is about the efficiency of the value of assets in the market to new informat

That's a different definition of efficient than efficient-market theory. The theory is about the efficiency of the value of assets in the market to new information. It isn't about the efficiency of the businesses in the market or the market overall. The stock market prices are efficient, not the stock market companies. Efficient-market theory doesn't apply to startups because they aren't listed on the stock exchange. The theory doesn't apply to small number of investors like VCs. It definitely doesn't apply to the business of the startup, or to the reaction of the market to the startup. It does apply when the startup goes public.