How does a change in market cap affect a company's operational decisions?
It basically only affects the company's dealings with its own stock, not with operational concerns.  If the company were to offer more stock for sale, it would get less cash.  If it had a stock buy-back program, it could buy more shares for the same money.  If it was to offer to acquire another company in exchange for its own stock, the terms would be less attractive to the other company's owners.  Employee stock remuneration, stock options, and so forth would be affected, so there might be considerations and tax consequences for the company. In practical terms, it shouldn't.  Market cap changes every day (assuming public trading, of course) or even second-by-second, and focusing on investor sentiment toward your company's stock is not the wisest way to make strategic decisions. That being said, company execs do need to be mindful of unusual swings in their company's share prices because it can sometimes be an indicator of news/information of which they're unaware.  At the same time, you can't just disregard your shareholders, especially the big institutional players who may have large voting blocks with which to replace you if they feel you're not responsive to events.  They are the ones who make strategic decisions based on your company's share price, right? (grin) The issue around swings in market cap is more about public perception than reality, so it is important for companies to have a good public relations strategy ready to go that can address questions/concerns in case of some market event.  After all, consumers who hear that a company's share price has suddenly fallen by, say, 30% might be more hesitant to do business with that company because there's a (perhaps irrational) fear the company's not doing well and may not be around much longer. Investors are, by their very nature, emotional rather than rational.  Any kind of news can cause a stampede toward or away from a stock for no reason that an investment professional could ever explain.  That's why it's impossible to spend any real time focusing on market cap (leave that to your P.R. department to worry about). IF, as a company executive, you focus on doing the right things to make your company successful then any questions/concerns about market cap will resolve themselves. Good luck!
The difference between the two numbers is that the market size of a particular product is expressed as an annual number ($10 million per year, in your example).  The market cap of a stock, on the other hand, is a long-term valuation of the company. In general, how does a large open market stock sale affect prices? A very general answer, all other things being equal, the price will move down. However there is nothing general. It depends on total number of shares in market and total turn over for that specific shares. The order book for the day etc. What is the maximum percentage of a company you could sell per day before the trading freezes, and what factors matter? Every stock exchange has rules that would determine when a particular stock would be suspended from trading, generally a 10-20% swing [either ways]. Generally highly liquid stock or stock during initial listing are exempt from such limits as they are left to arrive the market price ...  A large sell order may or may not swing the price for it to get suspended. At times even a small order may do ... again it is specific to a particular stock. It seems like you want to compare the company's values not necessarily the stock price.  Why not get the total outstanding shares and the stock price, generate the market cap.  Then you could compare changes to market cap rather than just share price. "If I held stock in these companies yesterday, would I have profited by these gains? No.  For DZSI, your 5 shares at $1.10 would now be 1 share at $5.50, so you would have the same total amount.  For SGY, they closed at $6.95, and opened at $32.80, so your five shares at $6.95 would now be one share at $32.80, so you would have actually lost money (not purely because of the split, but because the ""new"" shares are trading lower then the expected 1:5 split price).  A split in general does not affect market cap (how much your total shares are worth) but there may be residual effects that cause the market value to fluctuate after a split that affect the price." "Supply and Demand, pure and simple! There are two basic forms of this - a change in the quantity demanded/supplied at any given price, and a true change in the amount of demand/supply itself. Please note that this can be distinct from the underlying change in the value of the company and/or its expected future cash flows, which are a function of both financial performance and future expectations. If more people want the stock that are willing to sell it at a given price at a given point in time, sellers will begin to offer the stocks at higher prices until the market is no longer willing to bear the new price, and vice versa. This will reduce the quantity of stocks demanded by buyers until the quantity demanded and the quantity supplied once again reach an equilibrium, at which point a transaction occurs. Because people are motivated to buy and sell for different reasons at different times, and because people have different opinions on a constant flow of new information, prices change frequently. This is one of the reasons why executives of a recent IPO don't typically sell all of their stock at once. In addition to legal restrictions and the message this would send to the market, if they flooded the market with additional quantities of stock supplied, all else being equal, since there is no corresponding increase in the quantity demanded, the price would drop significantly. Sometimes, the demand itself for a company's stock shifts. Unlike a simple change in price driven by quantity supplied versus quantity demanded, this is a more fundamental shift. For example, let's suppose that the current demand for rare earth metals is driven by their commercial applications in consumer electronics. Now if new devices are developed that no longer require these metals, the demand for them will fall, regardless of the actions of individual buyers and sellers in the market. Another example is when the ""rules of the game"" for an industry change dramatically. Markets are behavioral. In this sense prices are most directly driven by human behavior, which hopefully is based on well-informed opinions and facts. This is why sometimes the price keeps going up when financial performance decreases, and why sometimes it does not rise even while performance is improving. This is also why some companies' stock continues to rise even when they lose huge sums of money year after year. The key to understanding these scenarios is the opinions and expectations that buyers and sellers have of that information, which is expressed in their market behavior." "I think the key concept here is future value.  The NAV is essentially a book-keeping exercise- you add up all the assets and remove all the liabilities.  For a public company this is spelled out in the balance sheet, and is generally listed at the bottom.  I pulled a recent one from Cisco Systems (because I used to work there and know the numbers  ;-) and you can see it here: roughly $56 billion... https://finance.yahoo.com/q/bs?s=CSCO+Balance+Sheet&annual  Another way to think about it: In theory (and we know about this, right?) the NAV is what you would get if you liquidated the company instantaneously.  A definition I like to use for market cap is ""the current assets, plus the perceived present value of all future earnings for the company""... so let's dissect that a little.  The term ""present value"" is really important, because a million dollars today is worth more than a million dollars next year.  A company expected to make a lot of money soon will be worth more (i.e. a higher market cap) than a company expected to make the same amount of money, but later.  The ""all future earnings"" part is exactly what it sounds like.  So again, following our cisco example, the current market cap is ~142 billion, which means that ""the market"" thinks they will earn about $85 billion over the life of the company (in present day dollars)." It is ALWAYS possible for a company's valuation in the market to be larger than the market it serves, and in fact it is not uncommon.  There's valid argument that Uber would be a good example of this, with a market cap of more than $60 billion.  Market cap is the total value of all shares outstanding.  Keep in mind that what a company's shares  trade for is less a reflection of its past (or, to some degree, even present) revenue activity and more of a speculative bet on what the company will do in the future. I remember my Finance Professor at b-school answering this question:   The next moment the dividend is paid the total market cap is decreased by the amount paid   This makes sense as cash leaves company, the value of the company is decreased by exactly the same amount. To summarise: the moment you paid dividend, the value of the stock is decreased by the same amount. There's an interesting paper, Does Investor Attention Affect Stock Prices? (Sandhya et al), where researchers look at related stock tickers.  When a large cap, better-known stock jumps, smaller firms with similar symbols also rise.   Pretty nuts -- I interviewed the author of the paper [here](http://www.tradestreaming.com/?p=3745). There's also a transcript. Large-scale price range of a stock isn't directly meaningful; that reflects how many shares exist, not just how desirable they are. A stock split, for example, doubles the number of shares everyone holds while cutting the value of each share in half; that's meaningless except that it makes the shares a bit easier to trade in. Change in price is more interesting. In the case of energy companies, that often reflects major changes in energy supply, distribution, use, or how well positioned people feel the company is for the next change in these. Fracking's surge and the questions raised against it, whether a major pipeline will or won't be built, international energy price trends, breakthroughs in renewables... if it might affect energy price, it might affect the company's strength, both absolute and relative to others. In other words, the same kinds of things that affect any stock. As said previously, most of the time volume does not affect stock prices, except with penny stocks. These stocks typically have a small volume in the 3 or 4 figure range and because of this they typically experience very sharp rises and drops in stock prices, contrasting normal stocks that go up and down constantly every minute. Volume is not one thing you should be looking at when analyzing a stock in most cases, since it is simply the number of people of trades made in a day. That has no effect on the value of the company, whereas looking at P/E ratios, dividend growth, etc all can be analyzed to see if a company is growing and is doing well in its field. If I buy an iPhone, it doesn't matter if 100 other people or 100,000 other people have bought it as well, since they won't really affect my experience with the product. Whereas the type of iPhone I buy will. Most of the money gained through PE is done through financial engineering/deal structuring. There are funds that are operationally focused which do make changes on the portfolio company level. From what I have seen, most people who are operationally focused do not achieve that much in the way of results. Picture it as consulting, except that the results of your initiatives are actually important.    As for turn-arounds, there are funds that specialize in that. Golden Gate Capital comes to mind. These are far more exciting investments, but can be very frustrating. If you want to look at it in terms of the public markets, turnarounds in PE are essentially levered value investments. It is likely that you aren't going to change the business much, but are actually just buying an out-of-favor business and waiting on the industry to bounce back.    The argument that PE funds just gut companies and sell with the new higher operating profitability is somewhat flawed. There is really only so much cost cutting you can do, once you have fired staff or corrected a mistake you won't likely have more chances to gain from that original problem. What people should be criticizing is that funds often cut capex and reinvestment to increase results at the expense of the future profitability of the company. "It is important to first understand that true causation of share price may not relate to historical correlation. Just like with scientific experiments, correlation does not imply causation. But we use stock price correlation to attempt to infer causation, where it is reasonable to do so. And to do that you need to understand that prices change for many reasons; some company specific, some industry specific, some market specific. Companies in the same industry may correlate when that industry goes up or down; companies with the same market may correlate when that market goes up or down. In general, in most industries, it is reasonable to assume that competitor companies have stocks which strongly correlate (positively) with each-other to the extent that they do the same thing.  For a simple example, consider three resource companies: ""Oil Ltd."" [100% of its assets relate to Oil]; ""Oil and Iron Inc."" [50% of its value relates to Oil, 50% to Iron]; and ""Iron and Copper Ltd."" [50% of its value relates to Iron, 50% to Copper]. For each of these companies, there are many things which affect value, but one could naively simplify things by saying ""value of a resource company is defined by the expected future volume of goods mined/drilled * the expected resource price, less all fixed and variable costs"". So, one major thing that impacts resource companies is simply the current & projected price of those resources. This means that if the price of Oil goes up or down, it will partially affect the value of the two Oil companies above - but how much it affects each company will depend on the volume of Oil it drills, and the timeline that it expects to get that Oil. For example, maybe Oil and Iron Ltd. has no currently producing Oil rigs, but it has just made massive investments which expect to drill Oil in 2 years - and the market expects Oil prices to return to a high value in 2 years.  In that case, a drop in Oil would impact Oil Inc. severely, but perhaps it wouldn't impact Oil and Iron Ltd. as much. In this case, for the particular share price movement related to the price of Oil, the two companies would not be correlated. Iron and Copper Ltd. would be unaffected by the price of Oil [this is a simplification; Oil prices impact many areas of the economy], and therefore there would be no correlation at all between this company's shares. It is also likely that competitors face similar markets. If consumer spending goes down, then perhaps the stock of most consumer product companies would go down as well. There would be outliers, because specific companies may still succeed in a falling market, but in generally, there would be a lot of correlation between two companies with the same market.  In the case that you list, Sony vs Samsung, there would be some factors that correlate positively, and some that correlate negatively. A clean example would be Blackberry stock vs Apple stock - because Apple's success had specifically negative ramifications for Blackberry. And yet, other tech company competitors also succeeded in the same time period, meaning they did not correlate negatively with Apple." "Market cap is speculative value, M = P * W, where W is stock (or other way of owning) percentage of ownership, P - price of percentage of ownership. This could include ""outside of exchange"" deals. Some funds could buy ownership percentage directly via partial ownership deal. That ownership is not stock, but fixed-type which has value too. Stock market cap is speculative value, M2 = Q * D, where D is free stocks available freely, Q - price of stock, in other words Quote number (not price of ownership). Many stock types do NOT provide actual percentage of ownership, being just another type of bond with non-fixed coupon and non-fixed price. Though such stocks do not add to company's capitalization after sold to markets, it adds to market capitalization at the moment of selling via initial price." "Does your planning include contingencies for Can you afford the late fees, insurance increases, bad credit hits and all the other downsides when this goes bad? Why does she NEED a new car on lease? Personally? I'd go for option B) Do what it takes to have her OWN a car. Why not just have her get a car that costs IN ENTIRE the $3k that would be used for a down payment on a lease? Maybe add a bit of your own money ""for old times sake"" to the pile? Or a small loan to get to where she can get a usable, dependable car? Say, a $3-5k loan in your name that she's responsible for the payments. $3-10k can get a very dependable old car. 10 great cars for 6k or less Everyone else has been burned by her - for whatever reason. No idea what the reasons are, but she seems to be unable to pay her bills. Why would this time be any different? Your name on a car + someone who can't pay bills = a bad proposition. I would LOVE to help anyone who's been important in my life. Including MY x-wife. But I wouldn't agree to this deal unless I KNEW that I could 100% cover the costs when things go bad - because at this point, odds are they will."