Which shareholders cause news-driven whole market stock swings?
The people who cause this sort of sell-off immediately are mostly speculators, short-term day-traders and the like. They realize that, because of the lowered potential for earnings in the future, the companies in question won't be worth as much in the future. They will sell shares at the elevated price, including sometimes shares that they borrow for the explicit purpose of selling (short selling), until the share price is more reasonable. Now, the other question is why the companies in question won't sell for as much in the future: Even if every other company in the world looks less attractive all at once (global economic catastrophe etc) people have other options. They could just put the money in the bank, or in corporate bonds, or in mortgage bonds, or Treasury bonds, or some other low-risk instrument, or something crazy like gold. If the expected return on a stock doesn't justify the price, you're unlikely to find someone paying that price. So you don't actually need to have a huge sell-off to lower the price. You just need a sell-off that's big enough that you run out of people willing to pay elevated prices. News-driven investors tend to be very short-term focussed investors. They often trade by using index futures (on the S&P 500 index for instance).
"Both explanations are partly true. There are many investors who do not want to sell an asset at a loss.  This causes ""resistance"" at prices where large amounts of the asset were previously traded by such investors.  It also explains why a ""break-through"" of such a ""resistance"" is often associated with a substantial ""move"" in price. There are also many investors who have ""stop-loss"" or ""trailing stop-loss"" ""limit orders"" in effect.  These investors will automatically sell out of a long position (or buy out of a short position) if the price drops (or rises) by a certain percentage (typically 8% - 10%). There are periods of time when money is flowing into an asset or asset class.  This could be due to a large investor trying to quietly purchase the asset in a way that avoids raising the price earlier than necessary.  Or perhaps a large investor is dollar-cost-averaging.  Or perhaps a legal mandate for a category of investors has changed, and they need to rebalance their portfolios.  This rebalancing is likely to take place over time.  Or perhaps there is a fad where many small investors (at various times) decide to increase (or decrease) their stake in an asset class.  Or perhaps (for demographic reasons) the number of investors in a particular situation is increasing, so there are more investors who want to make particular investments.  All of these phenomena can be summarized by the word ""momentum"". Traders who use technical analysis (including most day traders and algorithmic speculators) are aware of these phenomena.  They are therefore more likely to purchase (or sell, or short) an asset shortly after one of their ""buy signals"" or ""sell signals"" is triggered.  This reinforces the phenomena. There are also poorly-understood long-term cycles that affect business fundamentals and/or the politics that constrain business activity.  For example: Note that even if the markets really were a random walk, it would still be profitable (and risk-reducing) to perform dollar-cost-averaging when buying into a position, and also perform averaging when selling out of a position.  But this means that recent investor behavior can be used to predict the near-future behavior of investors, which justifies technical analysis." I don't think that you will be able to find a list of every owner for a given stock. There are probably very few people who would know this. One source would be whoever sends out the shareholder meeting mailers.  I suspect that the company itself would know this, the exchange to a lesser extent, and possibly the brokerage houses to a even lesser extent. Consider these resources: "Note that we do not comment on specific stocks here, and have no place doing so. If your question is only about that specific stock then it is off topic. I have not tried to answer that part below. The key to valuation is predicting the net present value of all of a company's cash flows; i.e. of their future profits and losses. Through a number of methods to long to explain here investment banks and hedge funds work out what they expect the company's cash flows to be and trade so that these future profits, losses etc. are priced into the stock price. Since future cash flows, profits or whatever you want to call them are priced in, the price of a stock shouldn't move at all on an earnings statement. This begs the question ""why do some stock prices move violently when they announce earnings?"" The models that the institutional investors use are not perfect and cannot take into account everything. An unexpected craze for a product or a supply chain agreement breaking down on not being as good as it seems will not be factored into this pricing and so the price will move based on the degree to which expectation is missed or exceeded. Since penny socks are speculative their value is based far more on the long term expected cash flows and less on the short run cash flows. This goes a long way to explaining why some of the highest market capitalisation penny stocks are those making consistent losses. This means that they can be far less susceptible to price movements after an earnings announcement even if it is well out of the consensus range. Higher (potential) future value comes with the higher risks of penny stocks which discounts current value. In the end if people's expectation of the company's performance reflects reality then the profitability is priced in and there will be no price movement. If the actuality is outside of the expected range then there will be a price movement." "The price of a company's stock at any given moment is established by a ratio of buyers to sellers.  When the sellers outnumber the buyers at a given price, the stock price drops until there are enough people willing to buy the stock to balance the equation again.  When there are more people wanting to purchase a stock at a given price than people willing to sell it, the stock price rises until there are enough sellers to balance things again.  So given this, it's easy to see that a very large fund (or collection of very large funds) buying or selling could drive the price of a stock in one direction or another (because the sheer number of shares they trade can tip the balance one way or another).   What's important to keep in mind though is that the ratio of buyers to sellers at any given moment is determined by ""market sentiment"" and speculation.  People selling a stock think the price is going down, and people buying it think it's going up; and these beliefs are strongly influenced by news coverage and available information relating to the company.  So in the case of your company in the example that would be expected to triple in value in the next year; if everyone agreed that this was correct then the stock would triple almost instantly.  The only reason the stock doesn't reach this value instantly is that the market is split between people thinking this is going to happen and people who think it won't.   Over time, news coverage and new information will cause one side to appear more correct than the other and the balance will shift to drive the price up or down.  All this is to say that YES, large funds and their movements CAN influence a stock's trading value; BUT their movements are based upon the same news, information, analysis and sentiment as the rest of the market.  Meaning that the price of a stock is much more closely tied to news and available information than day to day trading volumes.  In short, buying good companies at good prices is just as ""good"" as it's ever been.   Also keep in mind that the fact that YOU can buy and sell stocks without having a huge impact on price is an ADVANTAGE that you have.  By slipping in or out at the right times in major market movements you can do things that a massive investment fund simply cannot." "This is a classic correlation does not imply causation situation.  There are (at least) three issues at play in this question: If you are swing- or day-trading then the first and second issues can definitely affect your trading.  A higher-price, higher-volume stock will have smaller (percentage) volatility fluctuations within a very small period of time. However, in general, and especially when holding any position for any period of time during which unknowns can become known (such as Netflix's customer-loss announcement) it is a mistake to feel ""safe"" based on price alone. When considering longer-term investments (even weeks or months), and if you were to compare penny stocks with blue chip stocks, you still might find more ""stability"" in the higher value stocks.  This is a correlation alone — in other words, a stable, reliable stock probably has a (relatively) high price but a high price does not mean it's reliable. As Joe said, the stock of any company that is exposed to significant risks can drop (or rise) by large amounts suddenly, and it is common for blue-chip stocks to move significantly in a period of months as changes in the market or the company itself manifest themselves. The last thing to remember when you are looking at raw dollar amounts is to remember to look at shares outstanding.  Netflix has a price of $79 to Ford's $12; yet Ford has a larger market cap because there are nearly 4 billion shares compared to Netflix's 52m." In addition to the GE move, Buffett's firm also added a large share of Synchrony, equalling about $520.7 in value, and a $418.1 million stake in Store Capital.   So, they bought one regular sized share? This is Why BI-journalists doesnt work in IB... Generally speaking, having more institutional investors is a good sign. Of course there are many types of institutions.  Normally we are thinking of mutual funds, pension funds, endowments, and hedge funds.  They may not all have the same implications.  Hedge funds, in particular, are out to make a buck with very little restriction on how they do it.  They may buy an undervalued stock and then use their voting power to improve the company or they may do something more questionable, like pump up the stock price and then sell at the high, causing volatility.  The people you are referring to may be thinking of something like the latter. Those concerns are generally small when compared with the known positives of institutional ownership. When you look at the charts in Google Finance, they put the news on the right hand side. The time stamp for each news item is indicated with a letter in the chart. This often shows what news the market is reacting to. In your example:  Clicking on the letter F leads to this Reuters story: http://www.reuters.com/article/2011/02/04/usa-housing-s-idUSWAT01486120110204 In the United States, when key people in a company buy or sell shares there are reporting requirements.  The definition of key people includes people like the CEO, and large shareholders. There are also rules that can lock out their ability to buy and sell shares during periods where their insider knowledge would give them an advantage. These reporting rules are to level the playing field regarding news that will impact the stock price.  These rules are different than the reporting rules that the IRS has to be able to tax capital gains. These are also separate than the registration rules for the shares so that you get all the benefits of owning the stock (dividends, voting at the annual meeting, voting on a merger or acquisition). "Because more people bought it than sold it. That's really all one can say. You look for news stories related to the event, but you don't really know that's what drove people to buy or sell. We're still trying to figure out the cause of the recent flash crash, for example. For the most part, I feel journalism trying to describe why the markets moved is destined to fail.  It's very complicated. Stocks can fall on above average earnings reports, and rise on dismal annual reports. I've heard a suggestion before that people ""buy on the rumor, sell on the news"". Which is just this side of insider trading." I think the debacle they are referring to for Facebook's IPO is the Nasdaq debacle.   Nevertheless, Wall St ripped off retail investors pretty good with Facebook's IPO.   * Step One: Hype up major online company * Step Two: Overvalue IPO * Step Three: Sit back and watch the money roll in * Step Four: Watch all those suckers take losses and maybe even short the stock to make more money.  * Step Five: Repeat with next IPO.   Just business as usual with Wall St, when will America ever learn? More shares mean less volatility because it takes a larger number of trades, a larger number of shares per trade, or a combination of both to raise or lower the stock price. Institutional investors (mutual funds, pensions, hedge funds, other investment firms, etc) are the sorts of organizations with the large amounts of money needed to move a stock price one way or the other.  But the more floating shares there are in a company, the harder it is for one or two firms to move a stock price.  A company with fewer floating shares wouldn't require as many trades (or as many shares per trade) to see wider swings in price. When it comes to stock price, insider trading isn't the same as manipulation.  In the (surprisingly few) cases of insider trading that are prosecuted, it tends to be an individual (or small group) with early access to information that the broader market doesn't have being able to buy or sell ahead of the broader market.  Their individual sales are seldom if ever enough to noticeably move a stock price.  They're locking in profit or limiting a loss.  Manipulation might (but doesn't always) precede insider trading, if misinformation (or truth) is released for the purpose of creating a situation that can be profited from via a trade or trades. I think you're right, it is a big problem, and one without an apparant solution.  Because of the distributed nature of investors, it's difficult to organize them into a body that would seek and pay for suck ratings.  It's like a threesome principal agent problem.  In a perfect world, there would be more control exercised by investors.  But due to the manner in which the modern world saves, this is also very difficult. Stock prices are set by the market - supply and demand. See Apple for example, which is exactly the company you described: tons of earnings, zero dividends. The stock price goes up and down depending on what happens with the company and how investors feel about it, and it can happen that the total value of the outstanding stock shares will be less than the value of the underlying assets of the company (including the cash resulted from the retained earnings). It can happen, also, that if the investors feel that the stock is not going to appreciate significantly, they will vote to distribute dividends. Its not the company's decision, its the board's. The board is appointed by the shareholders, which is exactly why the voting rights are important. "What in the world to shareholders have to do with it?  Nowadays, the vast majority of the shares in most big corporations are ""owned"" via intermediaries (i.e. mutual funds and 401K's, IRA's and Pension Funds) that do not ALLOW the actual end owners to have any say whatsoever.  All those investment vehicles *allow* people to care about ... is the share price."