I'll grant that that's the commonly-accepted way to look at market cap, but I think it leaves out a crucial assumption: "Given the current supply and demand for

I'll grant that that's the commonly-accepted way to look at market cap, but I think it leaves out a crucial assumption: "Given the current supply and demand for/of the firm's equity". But I think that's not always a great assumption, because sometimes things happen that don't affect firm fundamentals (profit, revenues, margins) but do affect valuation, like changes in interest rates, shifting investor sentiment on the sector, a lighthouse investor publicly stating their intention to buy/sell, etc -- all of these things change market cap without altering the business per se. All this to say, I think the simple CAP=SHARES*PRICE formula is too simplistic. I think it's more accurate to think in terms of ranges of what the firm's equity might be worth, and realize that it's a highly subjective assessment based more on aggregate opinion, than some hard objective law of physics.