What causes discontinuities with stock prices
During the 12 plus hours the market was closed news can change investors opinion of the stock. When the market reopens that first trade could be much different than the last trade the day before.
"Thanks for pointing out [the study](http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1748851). It's a slightly different cause than what I was describing when I posted this. Specifically, they show an effect not when the names get confused, but rather when the name similarity simply brings more attention to the stock. I was surprised nobody mentioned that in response to my post.  But also interesting is that they had to control for simple confusion between stock symbols, which implies that ticker confusion has a known effect. So I dug into research on that and quickly found [this study](http://www.efmaefm.org/0EFMAMEETINGS/EFMA%20ANNUAL%20MEETINGS/2010-Aarhus/EFMA2010_0161_fullpaper.pdf) found ""a high positive correlation between returns on two matching stocks with similar ticker symbols""." The first statement is talking about a sudden sharp increase in volume (double or more of average volume) with a sudden increase in price. In other words, there has been a last rush to buy the stock exhausting all the current bulls (buyers), so the bears (sellers) take over, at least temporarily. Whilst the second statement is talking about a gradual increase in volume as the price up trends (thus the use of a volume oscillator). In other words (in an uptrend), the bulls (buyers) are gradually increasing in numbers sending the price higher, and new buyers keep entering the market. (The opposite is the case for a down-trend). "I think ""Psychological Pricing"" is a similar phenomenon to what you are looking for.  This is where retailers use certain numbers in prices because those prices are more appealing to consumers.  Since stocks - and in your case bitcoin - have prices, they too will be more or less appealing at different prices based on psychology alone." There is a technique called the Elliott wave which explains these 'shocks'. The reversal directions you are questioning are part of the pattern, it is known as corrections. The Elliott wave is an indicator based on psychology of investors. Think about it this way, if you see a huge up trend what are you most likely to do, sell and make profit or continue, this is why there is a shock before it continues. Many people will sell to be safe, especially after hearing the bad news they won't risk it. By learning the Elliott wave you'll be able to make an educated decision on whether or not to stay or leave. Here are websites on the Elliott wave: http://stockcharts.com/school/doku.php?id=chart_school:market_analysis:elliott_wave_theory http://www.swing-trade-stocks.com/elliott-wave.html The Elliott wave is helpful in any time frame and works well with momentum. Hope this helps. There are several reasons why this may happen and I will update as I get more information from you. Volumes on that stock look low (supposing that they are either in a factor between 1s and 1000s) so it could well be that there was no volume on that day. If no trades occur then open, high and low are meaningless as they are statistics based on trades that occur that day and no trades occur. Remember that there has to be volume to get a price. The stock may have been frozen by either the exchange or the company for the day. This could be for various reasons including to prevent some illegal activity. In that case no trades were made because the market for that stock was closed. Another possibility is that all trades that day were cancelled by the exchange. The exchange may cancel all trades if there is unusual, potentially fraudulent or other illegal activity on the stock. In this case the last price for that day existed but was rolled back by the exchange and never occurred. This is a rare situation. Although I can't find any holidays on that date it is possible that this is how your data provider marks market holidays. It would be valid to ignore the data in that case as being from a non-market day. I cannot tell if this is possible without knowing exchange information. There is a possibility that some data providers don't receive data for a day or that it gets corrupted. It may be worth checking another source to ensure the integrity of the data that you are receiving. Whichever reason is true, the data provider has made the close equal to the previous day's close as no price movements occurred. Strictly the closing price is the price of the last trade made for that day and so should be null (and open, high and low should be null too and not 0 otherwise the price change on day is very large!). Therefore, to keep integrity, you have a few choices: Okay I don't know where my disconnect was, in my mind I was viewing that as a negative for some reason haha. Thanks! That makes sense.  What is your perspective on the large amount of companies buying back shares right now? "What most of these answers here seem to be missing is that a stock ""price"" is not exactly what we typically expect a price to be--for example, when we go in to the supermarket and see that the price of a gallon of milk is $2.00, we know that when we go to the cash register that is exactly how much we will pay.  This is not, however, the case for stocks. For stocks, when most people talk about the price or quote, they are really referring to the last price at which that stock traded--which unlike for a gallon of milk at the supermarket, is no guarantee of what the next stock price will be.  Relatively speaking, most stocks are extremely liquid, so they will react to any information which the ""market"" believes has a bearing on the value of their underlying asset almost (if not) immediately.  As an extreme example, if allegations of accounting fraud for a particular company whose stock is trading at $40 come out mid-session, there will not be a gradual decline in the price ($40 -> $39.99 -> $39.97, etc.)-- instead, the price will jump from $40 to say, $20.  In the time between the the $40 trade and the $20 trade, even though we may say the price of the stock was $40, that quote was actually a terrible estimate of the stock's current (post-fraud announcement) price. Considering that the ""price"" of a stock typically does not remain constant even in the span of a few seconds to a few minutes, it should not be hard to believe that this price will not remain constant over the 17.5 hour period from the previous day's close to the current day's open.  Don't forget that as Americans go to bed, the Asian markets are just opening, and by the time US markets have opened, it is already past 2PM in London.  In addition to the information (and therefore new knowledge) gained from these foreign markets' movements, macro factors can also play an important part in a security's price-- perhaps the ECB makes a morning statement that is interpreted as negative news for the markets or a foreign government before the US markets open.  Stock prices on the NYSE, NASDAQ, etc. won't be able to react until 9:30, but the $40 price of the last trade of a broad market ETF at 4PM yesterday probably isn't looking so hot at 6:30 this morning... don't forget either that most individual stocks are correlated with the movement of the broader market, so even news that is not specific to a given security will in all likelihood still have an impact on that security's price. The above are only a few of many examples of things that can impact a stock's valuation between close and open: all sorts of geopolitical events, announcements from large, multi-national companies, macroeconomic stats such as unemployment rates, etc. announced in foreign countries can all play a role in affecting a security's price overnight. As an aside, one of the answers mentioned after hours trading as a reason--in actuality this typically has very little (if any) impact on the next day's prices and is often referred to as ""amateur hour"", due to the fact that trading during this time typically consists of small-time investors.  Prices in AH are very poor predictors of a stock's price at open." Stock markets have not been the cause of any of the problems. They display the symptoms of the problems, but they don't cause them.  The problems have been caused by the corruption of government (lobbying and political donations), insufficient, excessive and inappropriate regulation, and ignorance on the part of those who vote (demanding more services and less taxes and worrying more about wedge issues than sound governance). Are you sure you're not just looking at prices that are adjusted for the split, e.g. Yahoo? For example, Gilead Sciences (GILD) split a few months ago, but if you look at a price chart, there isn't an interruption even though the split is clearly marked. (Look in the past six months; it split in January). However, you could also simply be watching companies that happen to not split, for a variety of reasons. This isn't a criticism, but rather just a consequence of whatever stocks you happen to be watching.  However, a quick search for information on stock splits yields a few articles (mainly from the Motley Fool) that argue that fewer companies are performing stock splits in recent years; the articles mainly talk about tech companies, and they make the argument that even though the shares in Google and Apple have a high stock price: Google and Apple aren't all that expensive by traditional valuation   metrics. Google trades at just 15 times next year's projected   profitability. Apple fetches a mere 13 times fiscal 2012's bottom-line estimates. These articles are a bit dated in terms of the stock prices, but the rationale is probably still good. Similar logic could apply for other companies; for example, since May 2009, Panera's stock price has climbed by almost a factor of 4 without splitting. The articles also make the point that stock splits were traditionally seen as bullish signs because: Companies splitting to bring their share prices back down to more   accessible levels were optimistic in building those sand castles back   up. One could make a fair argument that the overall economic climate isn't as bullish as it used to be, although I would only be convinced that this was affecting stock splits if data could be gathered and tested. A stock split can also raise the price of a stock because if small investors feel the stock is suddenly more accessible to them, they purchase more of it and might therefore drive up the price. (See the Investopedia article on stock splits for more information). Companies might not see the necessity in doing this because their stock price isn't high enough to warrant a split or because the price isn't high enough to outprice smaller investors.  One interesting point to make, however, is that even though stock splits can drive small investors to buy more of the stock, this isn't always a gain for the company because professional investors (firms, institutions, etc.) have a tendency to sell after a split. The paper is a bit old, but it's still a very neat read. It's possible that more and more companies no longer see any advantage to splitting because it might not affect their stock price in the long run, and arguably could even hurt it. Considering that large/professional investors likely hold a higher percentage of a company's shares than smaller investors, if a stock split triggers a wave of selling by the former, the increasing propensity to buy of the latter may not be enough to offset the decline in price.  Note: My answer only refers to standard stock splits; the reasons above may not apply to a decrease in the number of reverse stock splits (which may not be a phenomenon; I don't know). "Your question contains a faulty assumption: During crashes and corrections the amount of sellers is of course higher than the amount of buyers, making it difficult to sell stocks. This simply isn't true.  Every trade has two sides; thus, by definition, for every seller there is buyer and vice versa.  Even if we broaden the definition of ""buyers"" and ""sellers"" to mean ""people willing to buy (or sell) at some price"", the assumption still isn't true.  When a stock is falling it is generally not because potential buyers are exiting the market; it is because they are revising the prices they are willing to buy at downward.   For example, say there are a bunch of orders to buy Frobnitz Consolidated (DUMB) at $5. Suppose DUMB announces a downward revision to its earnings guidance. Those people might not be willing to buy at $50 anymore, so they'll probably cancel their $50 buy orders.  However, just because DUMB isn't worth as much as they thought it was, that doesn't mean it's completely worthless.  So, those prospective buyers will likely enter new orders at some lower value, say, $45.  With that, the value of DUMB has just dropped by $5, a 10% correction.  However, there are still plenty of buyers, and you can still sell your DUMB holdings, if you're willing to take $45 for them. In other words, the value of a security is not determined by the relative numbers of buyers and sellers.  It is determined by the prices those buyers and sellers are willing to pay to buy or accept to sell.  Except for cases of massive IT disruptions, such as we saw in the ""flash crash"", there is always somebody willing to buy or sell at some price." Volumes are used to predict momentum of movement, not the direction of it. Large trading volumes generally tend to create a price breakout in either positive or negative direction. Especially in relatively illiquid stocks (like small caps), sudden volume surges can create sharp price fluctuations. Aside from the market implications Victor and JB King mention, another possible reason is the dividends they pay. Usually, the dividends a company pays are dependent on the profit the company made. if a company makes less profit, the dividends turn out smaller. This might incite unrest among the shareholders, because this means that they get paid less dividends, which makes that share more likely to be sold, and thus for the price to fall. "The share price on its own has little relevance without looking at variations. In your case, if the stock went from 2.80 to 0.33, you should care only about the 88% drop in value, not what it means in pre-split dollar values. You are correct that you can ""un-split"" to give you an idea of what would have been the dollar value but that should not give you any more information than the variation of 88% would. As for your title question, you should read the chart as if no split occurred as for most intents and purposes it should not affect stock price other than the obvious split." according to me it's the news about a particular stock which makes people to buy or sell it mostly thus creates a fluctuation in price . It also dependents on the major stock holder. You would think that share prices is just a reflection of how well the company is doing but that is not always the case. Sometimes it reflects the investor confidence in the company more than the mere performance. So for instance if some oil company causes some natural disaster by letting one of there oil tankers crash into a coral reef then investor confidence my take a big hit and share prices my fall even if the bottom line of the company was not all that effected.