should the Market Capitalization be equal to the Equity of the firm
"Lots of questions: In general, no. Market Capitalization and Equity represent 2 different things.  Equity first, the equity of a firm is the value of the assets (what it owns) less its liabilities (what it owes) and consists (broadly) of two components - share capital (what the firm gets when it sells to investors as part of an IPO or subsequent share issue) and retained earnings (what the firm has as a result of making profits and not paying them out as dividends). This is the theoretical liquidation value of the firm - what it is worth if it stops trading, sells all its assets and pays all its debts. Market Capitalization is the current value of the future cash flow of the firm as perceived by the market - the value today of all the dividends that the firm will pay in the future for as long as it exists. This is the theoretical going concern value of the firm - what it is worth as a functioning business. In general, Market Capitalization is bigger than Equity - if it isn't the firm is worth more as scrap than as an operating business. Um ... no. If you don't have any shares then you are by definition not an owner. Having shares is what makes you an owner. What I think you mean is, is it possible for the owner(s) of a private company to sell all of its shares when it goes public? The answer is yes. It is uncommon for a start-up owner to do this but it is standard practice for ""corporate raiders"" who buy failing companies, take them private, restructure them and then take them public again - they have done their job and they are not interested in maintaining an ownership stake. Nope. See above and below. Not at all, equity is an accounting construct and market capitalization is about market sentiment. Consider the following hypothetical firm: It has $1m in equity, it makes $4m in profit and will do for the foreseeable future, it pays all of that $4m out as dividends - if we work on a simple ROI of 10% then this firm is worth $40m dollars - way more than its equity."
Imagine a poorly run store in the middle of downtown Manhattan. It has been in the family for a 100 years but the current generation is incompetent regarding running a business. The store is worthless because it is losing money, but the land it is sitting on is worth millions.  So yes an asset of the company can be worth more than the entire company.  What one would pay for the rights to the land, vs the entire company are not equal. Market cap should be share price times number of shares, right? That's several orders of magnitude right there... Proportional is good, but we don't need redistribution. The market mechanism does that on its own when it's free. The bailouts of the banks and auto industry should have shown that the only thing stopping a major, but poorly run business from bankruptcy (and having its assets redistributed) is government intervention.  Maybe the change will light a fire under complacent companies and they'll start earning their profits again, or maybe they'll fail. There's no way to know ahead of time, but with no legal barriers to entry, the playing field will be fair again. "Some companies issue multiple classes of shares.  Each share may have different ratios applied to ownership rights and voting rights.  Some shares classes are not traded on any exchange at all.  Some share classes have limited or no voting rights.   Voting rights ratios are not used when calculating market cap but the market typically puts a premium on shares with voting rights. Total market cap must include ALL classes of shares, listed or not, weighted according to thee ratios involved in the company's ownership structure.  Some are 1:1, but in the case of Berkshire Hathaway, Class B shares are set at an ownership level of 1/1500 of the Class A shares. In terms of Alphabet Inc, the following classes of shares exist as at 4 Dec 2015: When determining market cap, you should also be mindful of other classes of securities issued by the company, such as convertible debt instruments and stock options.  This is usually referred to as ""Fully Diluted"" assuming all such instruments are converted." The book value is Total Assets minus Total Liabilities and so if you increase the Total Assets without changing the Total Liabilities the difference gets bigger and thus higher. Consider if a company had total assets of $4 and total liabilities of $3 so the book value is $1. Now, if the company adds $2 to the assets, then the difference would be 4+2-3=6-3=3 and last time I checked 3 is greater than 1. On definitions, here are a couple of links to clarify that side of things. From Investopedia: Equity = Assets - Liabilities From Ready Ratios: Shareholders Equity = Total Assets – Total Liabilities OR Shareholders Equity = Share Capital + Retained Earnings – Treasury   Shares Depending on what the reinvestment bought, there could be several possible outcomes. If the company bought assets that appreciated in value then that would increase the equity. If the company used that money to increase sales by expanding the marketing department then the future calculations could be a bit trickier and depend on what assumptions one wants to make really. If you need an example of the latter, imagine playing a game where I get to make up the rules and change them at will. Do you think you'd win at some point? It would depend on how I want the game to go and thus isn't something that you could definitively say one way or the other. "The answer to your question depends on what you mean when you say ""growth"".  If you mean a literal increase in the aggregate market capitalization of companies, across the entire market, then, no, this sort of growth is not possible without concomitant economic growth.  The reason why is that the market capitalization of each company is proportional to its gross revenue, and the sum of all revenue from selling ""final goods"" (i.e., things purchased and used by consumers) is, apart from a few technicalities, the definition of GDP.  The exact multiplier might fluctuate up or down depending on investors' expectations about how sales will grow or decline going forward, but in a zero-growth economy this multiplier should be stable over the long run.  It might, however, still fluctuate over the short term, but more about that in a minute.   Note that all of this applies to aggregate growth across all firms.  Individual firms can still grow, of course, but as they must do this by gaining market share from other companies such growth would be balanced by a decline for some other firm.  Also, I've assumed zero net exports (that's one of the ""technicalities"" I mentioned above) because obviously you could have export-driven growth even if the domestic economy were stationary. However, often when people talk about ""growth"" in the market, what they really mean is ""return"".  That is, how much does your investment earn for you.  This isn't really the same thing as growth, but people often think of it that way, particularly in the saving phase of their investing career, when they are reinvesting their returns, and therefore their account balances are growing.  It is possible to have a positive return, averaged across the market, even in a stationary economy.  The reason why is that there are really only two things a firm can do with its net profits.  One possibility is that it could invest it in growing the business.  However, there is not much point in doing that in a stationary economy because by assumption no increase in aggregate consumption (and therefore, in the long run, aggregate production) are possible.  Therefore, firms are left with only the second option, which is to pay them out to investors as dividends.  Those dividends provide a return that is independent of economic growth. Would the stock market still be a good investment in such an economy?  Yes.  Well, sort of.  The rate of return from firms' dividend payouts will depend on investors' demand (in aggregate) for returns on their investments.  Stock prices will rise or fall, causing returns to respectively fall or rise, to find that level.  If your personal desire for returns is lower than the average across the investing public, then the stock market would look like a good investment.  If your desired return is higher than the average, then it will look like a poor investment.  The marginal investor will, of course be indifferent.  The practical upshot of this is that the people who invest in the stock market in this scenario will be precisely the ones for whom the stock market is a good investment, given their personal propensity to save and desire for returns, and so forth. Finally, you mentioned that in your scenario the GDP stagnation is due to declining population.  I am less certain what this means for investment, but my first thought is that you would have a large retired population selling its investments to fund late-life consumption, and you would have a comparatively small (relative to history) working population buying those assets.  This would lead to low asset prices, and therefore high rates of return.  However, that's assuming that retirees need to sell assets to fund their retirement consumption.  If the absolute returns on retirees' assets are large enough to fund their retirement consumption then you would wind up with relatively few sellers, resulting in high prices and therefore relatively low rates of return.  It's not obvious to me which effect would dominate, and so it's hard to say whether or not the resulting returns would look attractive to the working-age population." none of which give a good return if the underlying economy is shit. the underlying economy will be shit if there hasn't been sufficient investment in more productive endeavors. if the underlying economy hasn't been sufficiently capitalized, that will present juicy returns to investors.   it's a complete substance-less threat that if we fail to continue to coddle the rentiers, the economy will collapse because they'll do X with their money (X being something other than maximizing return) "At any given moment, one can tally the numbers used for NAV. It's math, and little more. The Market Cap, which as you understand is a result of share value. Share value (stock price) is what the market will pay today for the shares. It's not only based on NAV today, but on future expectations. And expectations aren't the same for each of us. Which is why there are always sellers for the buyers of a stock, and vice-versa.  From your question, we agree that NAV can be measured, it's the result of adding up things that are all known. (For now, let's ignore things such as ""goodwill."") Rarely is a stock price simply equal to the NAV divided by the number of shares. Often, it's quite higher. The simplest way to look at it is that the stock price not only reflects the NAV, but investors' expectations looking into the future.  If you look for two companies with identical NAV per share but quite different share prices, you'll see that the companies differ in that one might be a high growth company, the other, a solid one but with a market that's not in such a growth mode." "If you look at the biotech breakdown, you'll find a lot of NAs when it comes to P/E since there are many young biotech companies that have yet to make a profit.  Thus, there may be something to be said for how is the entire industry stat computed. Biotechnology can include pharmaceutical companies that can have big profits due to patents on drugs. As an example, look at Shire PLC which has a P/E of 1243 which is pretty high with a Market Capitalization of over a billion dollars, so this isn't a small company.  I wonder what dot-com companies would have looked like in 1998/1999 that could well be similar as some industries will have bubbles you do realize, right? The reason for pointing out the Market Capitalization is that this a way to measure the size of a company, as this is merely the sum of all the stock of the company.  There could be small companies that have low market capitalizations that could have high P/Es as they are relatively young and could be believed to have enough hype that there is a great deal of confidence in the stock.  For example, Amazon.com was public for years before turning a profit.  In being without profits, there is no P/E and thus it is worth understanding the limitations of a P/E as the computation just takes the previous year's earnings for a company divided by the current stock price.  If the expected growth rate is high enough this can be a way to justify a high P/E for a stock.  The question you asked about an industry having this is the derivation from a set of stocks.  If most of the stocks are high enough, then whatever mean or median one wants to use as the ""industry average"" will come from that." "From Wikipedia: Usage Because EV is a capital structure-neutral metric, it is useful when   comparing companies with diverse capital structures. Price/earnings   ratios, for example, will be significantly more volatile in companies   that are highly leveraged. Stock market investors use EV/EBITDA to compare returns between   equivalent companies on a risk-adjusted basis. They can then   superimpose their own choice of debt levels. In practice, equity   investors may have difficulty accurately assessing EV if they do not   have access to the market quotations of the company debt. It is not   sufficient to substitute the book value of the debt because a) the   market interest rates may have changed, and b) the market's perception   of the risk of the loan may have changed since the debt was issued.   Remember, the point of EV is to neutralize the different risks, and   costs of different capital structures. Buyers of controlling interests in a business use EV to compare   returns between businesses, as above. They also use the EV valuation   (or a debt free cash free valuation) to determine how much to pay for   the whole entity (not just the equity). They may want to change the   capital structure once in control. Technical considerations Data availability Unlike market capitalization, where both the market price and the   outstanding number of shares in issue are readily available and easy   to find, it is virtually impossible to calculate an EV without making   a number of adjustments to published data, including often subjective   estimations of value: In practice, EV calculations rely on reasonable estimates of the   market value of these components. For example, in many professional   valuations: Avoiding temporal mismatches When using valuation multiples such as EV/EBITDA and EV/EBIT, the   numerator should correspond to the denominator. The EV should,   therefore, correspond to the market value of the assets that were used   to generate the profits in question, excluding assets acquired (and   including assets disposed) during a different financial reporting   period. This requires restating EV for any mergers and acquisitions   (whether paid in cash or equity), significant capital investments or   significant changes in working capital occurring after or during the   reporting period being examined. Ideally, multiples should be   calculated using the market value of the weighted average capital   employed of the company during the comparable financial period. When calculating multiples over different time periods (e.g. historic   multiples vs forward multiples), EV should be adjusted to reflect the   weighted average invested capital of the company in each period. In your question, you stated: The Market Cap is driven by the share price and the share price is   determined by buyers and sellers who have access to data on cash and   debts and factor that into their decision to buy or sell. Note the first point under ""Technical Considerations"" there and you will see that the ""access to data on cash and debts"" isn't quite accurate here so that is worth noting. As for alternatives, there are many other price ratios one could use such as price/earnings, price/book value, price/sales and others depending on how one wants to model the company. The better question is what kind of investing strategy is one wanting to use where there are probably hundreds of strategies at least. Let's take Apple as an example. Back on April 23, 2014 they announced earnings through March 29, 2014 which is nearly a month old when it was announced. Now a month later, one would have to estimate what changes would be made to things there. Thus, getting accurate real-time values isn't realistic. Discounted Cash Flow is another approach one can take of valuing a company in terms of its future earnings computed back to a present day lump sum." The market cap always reflect the company's equity.  Except that you cannot fix a stock price in a free market.  A company with such profit pattern would have stock price behave like present value of a perpetuity (future income stream discounted by risk free rate) Since your assumption is unachievable, there is no point in determining the logic. "If your business is structured as a partnership or sole proprietorship you call this investment ""partner equity"".  If instead it is structured as a corporation, then the initial investment is called ""paid-in capital"".  Either way, this represents the capital the initial investors or partners provided to the company in exchange for their ownership stake. The most important thing in your case is that since that initial investment is in the form of inventory, you are going to have to document the value of that investment somehow.  You will definitely need a comprehensive manifest of what you contributed, including titles and condition, and if possible you should document the prices at which similar items are being offered for sale at the time you start operating.  Having this information will support your claims as to the fair market value of the start-up contribution, should the tax authorities decide to question it." How are shareholders sure to receive a fair percentage of each company?  At the time the split occurs, each investor owns the same proportion of each new company that they owned in the first.  What the investor does with it after that (selling one, for example) is irrelevant from a fairness perspective. Suppose company A splits into companies B and C.  You own enough stock to have 1% of A.  It splits.  Now you have a bunch of shares of B and C.  How much?  Well, you have 1% of B and 1% of C.  What if all the profitable projects are in B?  Then shares of B will be worth more than those of C.  But it should be the case that the value of your shares of B plus the value of your shares of C are equal to the original value of your shares of A.  Completely fair.  In fact, if the split was economically justified, then B + C > A.  And the gains are realized proportionally by all equityholders. Remember, when a stock splits, every share splits so that everyone owns both companies in the same proportion as everyone else.  Executives don't determine what the prices of the resulting companies are...that is determined by the market.  A fair market will value the child companies such that together they are worth what the original was. On a company level ROCE over WACC would be more meaningful in my view but the end result should be be pretty much the same. This concept is closely related to value creation. Value can only be created when a company's ROCE is exceeding its cost of funding - WACC. This is also tightly related with the NPV concept. Value is only created when the NPV on a project is &gt;0.  And to directly answer OP. Study in detail WACC. (weighted average cost of capital). Focus on the Modigliani–Miller theorem with taxes and financial distress costs. Good luck. I think the most concise way to understand EV is the value of the *operating assets* of the firm. It's most generally used when using income statement or cash flow ratios that are unlevered - before applying interest expense (which if the firm is optimally financed, in theory should only impact the equity). Examples include revenue, EBIT, EBITDA, unlevered FCF, etc.  In your hypothetical scenario, you would expect the equity value of the firm to increase linearly as cash builds up. In other words, in some implausible, ceteris paribus formulation of the firm, the enterprise value should remain constant.