Why do some services list an IPO date that is well after historical price data you can find elsewhere?
"The Minnesota Mining and Manufacturing Company was established in 1902 as a private company.  It first raised public funds around 1903 but had a limited shareholder base.  By around 1929, it was reported as being tradeable as an OTC (over-the-counter) stock but it's likely that shares were traded well before this.  On 14 Jan 1946, the stock was listed on NYSE.  On 26 Sep 1962 it became a constituent of the the S&P 500 index.  On 9 Aug 1976 it became a constituent of the Dow Jones Industrial Average. In 2002, the company's name changed to 3M Co. It appears that the data on Crunchbase's ""IPO Date"" is wrong on this one. However, there are several companies that appear to do an ""IPO"" and have trading prices prior.  This is quite typical of early-stage biotech companies that trade OTC prior to a major exchange listing and ""IPO"". An example of an IPO happening after a company became publicly tradeable is NASDAQ:IMRN (Immuron). They had an ""IPO"" on Nasdaq on 9 Jun 2017, yet they had been trading as an OTC/Pink Sheet stock for months prior. They also have been listed in Australia since 30 Apr 1999. http://www.nasdaq.com/markets/ipos/activity.aspx?tab=pricings&month=2017-06 Another example is NASDAQ:GNTY (Guaranty Banchshares Inc) which had an ""IPO"" and NASDAQ listing in May 2017. This was a Nasdaq stock in 1998, went OTC/pink sheet stock in 2005. It has been paying regular dividends since that time. Clearly the word ""Initial"" is subjective!  http://www.nasdaq.com/markets/ipos/activity.aspx?tab=pricings&month=2017-05"
Various types of corporate actions will precipitate a price adjustment.  In the case of dividends, the cash that will be paid out as a dividend to share holders forms part of a company's equity.  Once the company pays a dividend, that cash is no longer part of the company's equity and the share price is adjusted accordingly. For example, if Apple is trading at $101 per share at the close of business on the day prior to going ex-dividend, and a dividend of $1 per share has been declared, then the closing price will be adjusted by $1 to give a closing quote of $100. Although the dividend is not paid out until the dividend pay date, the share price is adjusted at the close of business on the day prior to the ex-dividend date since any new purchases on or after the ex-dividend date are not entitled to receive the dividend distribution, so in effect new purchases are buying on the basis of a reduced equity.   It will be the exchange providing the quote that performs the price adjustment, not Google or Yahoo.  The exchange will perform the adjustment at the close prior to each ex-dividend date, so when you are looking at historical data you are looking at price data that includes each adjustment. "I can't speak authoritatively to your broader question about stocks in general, but in several years tracking AAPL closely, I can tell you that there's little apparent pattern to when their earnings call will be, or when it will be announced. What little I do know:  - AAPL's calls tend to occur on a Tuesday more than any other day of the week  - it's announced roughly a month in advance, but has been announced w/ less notice  - it has a definite range of dates in which it occurs, typically somewhere in the 3rd week of the new quarter plus or minus a few days More broadly for #1: Given the underlying nature of what an option is, then yes, the day an earnings call date is announced could certainly influence the IV/price of options - but only for options that expire inside the ""grey area"" (~2 weeks long) window in which the call could potentially occur.  Options expiring outside that grey area should experience little to no price change in reaction to the announcement of the date - unless the date was itself surprising, e.g. an earlier date would increase the premium on earlier dated options, a later date would increase the premium for later-dated options. As for #2: The exact date will probably always be a mystery, but the main factors are:  - the historical pattern of earnings call dates (and announcements of those dates) which you can look up for any given company  - when the company's quarter ends  - potentially some influence in how long it takes the company to close out their books for the quarter (some types of businesses would be faster than others)  - any special considerations for this particular quarter that affect reporting ability And finally:   - a surprise of an earnings call occurring (substantively) later than usual is rarely going to be a good sign for the underlying security, and the expectation of catastrophe - while cratering the underlying - may also cause a disproportionate rise in IVs/prices due to fear" "Changing my answer based on clarification in comments. It appears that some of the securities you mentioned, including GEAPP, are traded on what is colloquially known as the Grey Market. Grey Sheets, and also known as the ""Gray Market"" is another category of OTC stocks that is completely separate from Pink Sheets and the OTCBB.  From investopedia The grey market is an over-the-counter market where dealers may execute orders for preferred customers as well as provide support for a new issue before it is actually issued. This activity allows underwriters and the issuer to determine demand and price the securities accordingly before the IPO.  Some additional information on this type of stocks. (Source) Unlike other financial markets... No recent bid or ask quotes are available because no market makers share data or quote such stocks. There is no quoting system available to record and settle trades. All Grey sheet trading is moderated by a broker and done between consenting individuals at a price they agree on. The only documentation that can be publicly found regarding the trades is when the last trade took place. No SEC registration and little SEC regulation. Regulation of Grey Sheet stocks takes place mainly on a state level. Unlike Pink Sheets, these stocks have no SEC registration to possess a stock symbol or to possess shares or trade shares of that stock. Such penny stocks, similar to Pink Sheets, are not required to file SEC (Securities and Exchange Commission) financial and business reports. These stocks may not be solicited or advertised to the public unless a certain number of shares are qualified to be traded publicly under 504 of Regulation D. Extremely Illiquid. Gray sheet trading is infrequent, and for good reason... Difficult to trade, not advertised, difficult to follow the price, the least regulation possible, hard to find any information on the stock, very small market cap, little history, and most such stocks do not yet offer public shares. The lack of information (bids, history, financial reports) alone causes most investors to be very skeptical of Gray Sheets and avoid them altogether.  Gray Sheets are commonly associated with Initial public offering (IPO) stocks or start up companies or spin-off companies, even though not all are IPO's, start-ups or spin-offs. Grey Sheets is also Home to delisted stocks from other markets. Some stocks on this financial market were once traded on the NASDAQ, OTCBB, or the Pink Sheets but ran into serious misfortune - usually financial - and thus failed to meet the minimum requirements of the registered SEC filings and/or stock exchange regulations for a financial market. Such stocks were delisted or removed and may begin trading on the Grey Sheets.  So to answer your question, I think the cause of the wild swings is that:   Great question, BTW." It's a drive by swipe at technicals, which is fine and all, but I always thought technicals effectively provide odds of an event happening. For example, $XYZ price is a support level, therefore there are increased odds it will bounce higher from these levels, rather than an implied *guarantee* the support will hold. 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. The data for ES_F normally is joined on the contract expiry date, i.e. june is joined to the next month on the expiry date.  The discrepancy to the real thing in practice might be significant, as seasonal strategies (as we call these) are mined fairly often. "Usually the big institution that ""floats"" the stock on the market is the one to offer it to you. The IPO company doesn't sell the stock itself, the big investment bank does it for them. IPO's shareholders/employees are generally not allowed to sell their shares at the IPO until some time passes. Then you usually see the sleuth of selling." Out of curiosity I went through a couple of prospectuses and all contained various clauses for the event where LIBOR is not published although the language suggests more of anticipation of brief technical difficulties. Some are rather vague and prone to manipulation. "Often you are right, and the current information is ""priced in"", but I would say in times of market boom like this that the market can definitely overprice. Price is driven by trades/last trade. Someone may be willing to pay X, and do so, making the price now X, but that does not mean it is worth X. You could very well be paying a premium for it's perceived desirability. This is why investors/analysts spend time and energy on valuations, they want to compare the markets current price to what the price theoretically should/would be if it were purely driven by the data, in effect trying to remove sentiment from the equation to gain a more realistic idea of what a company is worth.  Side note adding on that, don't mistake this as saying one should pay a lot of attention to analysts or their price targets, though analysts do have insightful things to say." After a company goes public, if it wants to raise more money, then it does this by secondary public offering or rights issue. In subscription rights issue gives the right to existing share holders to buy new shares at equal proportion. So if every one buys, they maintain the same percentage of ownership. Generally the pricing is at discount to current market price. Not sure why the price is high, unless the price for this stock fell sharply recently. "There are two scenarios to determine the relevant date, and then a couple of options to determine the relevant price. If the stocks were purchased in your name from the start - then the relevant date is the date of the purchase. If the stocks were willed to you (i.e.: you inherited them), then the relevant date is the date at which the person who willed them to you had died. You can check with the company if they have records of the original purchase. If it was in ""street name"" - they may not have such records, and then you need to figure out what broker it was to hold them. Once you  figured out the relevant date, contact the company's ""investor relationships"" contact and ask them for the adjusted stock price on that date (adjusted for splits/mergers/acquisitions/whatever). That would be the cost basis per share you would be using. Alternatively you can research historical prices on your favorite financial information site (Google/Yahoo/Bloomberg or the stock exchange where the company is listed). If you cannot figure the cost basis, or it costs too much - you can just write cost basis as $0, and claim the whole proceeds as gains. You'll pay capital gains tax on the whole amount, but that may end up being cheaper than conducting the investigation to reveal the actual numbers." "To add to @keshlam's answer slightly a stock's price is made up of several components: the only one of these that is known even remotely accurately at any time is the book value on the day that the accounts are prepared. Even  completed cashflows after the books have been prepared contain some slight unknowns as they may be reversed if stock is returned, for example, or reduced by unforeseen costs.  Future cashflows are based on (amongst other things) how many sales you expect to make in the future for all time. Exercise for the reader: how many iPhone 22s will apple sell in 2029? Even known future cashflows have some risk attached to them; customers may not pay for goods, a supplier may go into liquidation and so need to change its invoicing strategy etc.. Estimating the risk on future cashflows is highly subjective and depends greatly on what the analyst expects the exact economic state of the world will be in the future. Investors have the choice of investing in a risk free instrument (this is usually taken as being modelled by the 10 year US treasury bond) that is guaranteed to give them a return. To invest in anything riskier than the risk free instrument they must be paid a premium over the risk free return that they would get from that. The risk premium is related to how likely they think it is that they will not receive a return higher than that rate. Calculation of that premium is highly subjective; if I know the management of the company well I will be inclined to think that the investment is far less risky (or perhaps riskier...) than someone who does not, for example. Since none of the factors that go into a share price are accurately measurable and many are subjective there is no ""right"" share price at any time, let alone at time of IPO. Each investor will estimate these values differently and so value the shares differently and their trading, based on their ever changing estimates, will move the share price to an indeterminable level. In comments to @keshlam's answer you ask if there is enough information to work out the share price if a company buys out the company before IPO. Dividing the price that this other company paid by the relative ownership structure of the firm would give you an idea of what that company thought that the company was worth at that moment in time and can be used as a surrogate for market price but it will not and cannot accurately represent the market price as other investors will value the firm differently by estimating the criteria above differently and so will move the share price based on their valuation." "In the case of an ""initial public offering"", the brokers underwriting the share issue will look at the current earnings being generated by the company and compare these to those of other competitor companies already listed in the stock market.  For example, if a new telephone company is undertaking an initial public offering, then the share price of those telephone companies which are already traded on the stock market will serve as a reference for how much investors will be willing to pay for the new company's shares.  If investors are willing to pay 15 times earnings for telecom shares, then this will be the benchmark used in determining the new share price. In addition, comparative growth prospects will be taken into account.  Finally, the underwriter will want to see a successful sale, so they will tend to ""slightly under price"" the new shares in order to make them attractive. None of this is an exact science and we often see shares trading at a large premium to the initial offer price during the first few days of trading.  More often that not, prices then settle down to something closer to the offer price.  The initial price spike is usually the result of high demand for the shares by investors who believe that past examples of a price spike will repeat with this initial public offering.  There will also usually be high demand for the new shares from funds that specialise in shares of the type being issued. In the case of a ""rights issue"", where an existing publicly traded company wishes to raise capital by issuing new shares, the company will price the new shares at a significant discount to the current market price.  The new shares will be initially offered to existing shares holders and the discounted price is intended to encourage the existing shareholders to exercise their ""rights"" since the new shares may have the effect of diluting the value of their shares.  Any shares which are not purchased by existing share holder will then be offered for sale in the market." The cause of incomplete/inaccurate financial data's appearing on free sites is that it is both complicated and expensive to obtain and parse these data. Even within a single country, different pieces of financial data are handled by different authorities.  In the US, for example, there is one generally recognized authority for stock prices and volumes (CQS), but a completely different authority for corporate earnings data (SEC).  For futures and options data the only authority is each individual exchange.  Each of these sources might have a vastly different interface to their data; some may have websites, others may have FTPs, others may have TCP datastreams to which you must subscribe, etc. Now throw in the rest of the world and all their exchanges and regulatory agencies, and you can see how it's a difficult job to gather all this information, parse it on a daily (or more frequent) basis, and check it all for errors. There are some companies (e.g. Bloomberg) whose entire business model is to do the above.  They spend tens of millions of dollars per year to support the infrastructure and manpower required to keep such a complex system working, and they charge their consumers a pretty penny in return. Do Google/Yahoo pay for Bloomberg data access just to display information that we then consume for free?  Maybe.  Maybe they pay for some less expensive reduced data set.  Or a data set that is less rigorously checked for errors. Even if they pay for the best data available, there's no guarantee that a company's last earnings report didn't have a glitch in it, or that Bloomberg's latest download from the Canadian Agency for Corporate Dividends and Moose Census-Taking didn't get cut off in the middle, or that the folks at Yahoo built a robust system that can handle a particular file's not arriving on time.  Bloomberg has dozens or even hundreds of employees focused on just this one task; Yahoo probably has 5. Moral: If you really need the best available data you must go to the source(s), or you must pay a provider to whom you can then complain when something is wrong.  With free data you get what you pay for. Adjustments can be for splits as well as for dividends.  From Investopedia.com: Historical prices stored on some public websites, such as Yahoo!   Finance, also adjust the past prices of the stock downward by the   dividend amount. Thus, that could also be a possible factor in looking at the old prices.