Sure, if they tried to spend all of their assets on buying back all of the existing stock that would be a sign they might be going bankrupt. Alternately, maybe

Sure, if they tried to spend all of their assets on buying back all of the existing stock that would be a sign they might be going bankrupt. Alternately, maybe the market cap isn't a perfect representation of how much a company is worth and it's a reflection of a complex array of factors that aren't easily explained away in favor of a simple narrative.