Why would a company have 2 listings on the same exchange?
A company can issue different kinds of shares. For example, some kinds of shares may get preference in dividends or payment in event of (company) bankruptcy. Preferred shares are an example of this. A company might have several kinds of preferred shares and a 'common stock'. Here is a good explanation. See too the Wikipedia article about preferred stock. Toronto-Dominion Bank (TD) is an example of a company that has fourteen different preferred share issues, each with its own listing on the Toronto Stock Exchange (TSE) and symbol. TD has one kind of common stock, which is also listed on the TSE. However, TD common equity trades much more actively than the preferred shares. Remember that preferred stock is a different security type than common stock e.g. common has voting rights, preferred does not. Some companies like Royal Dutch Shell have multiple share classes to suit the tax regimes in Holland and the UK the A shares have dutch withholding tax applied and the B shares dont.  Also some split capital investment trusts have multiple share classes http://www.trustnet.com/Education/Split.aspx?ms=1
Just because it gets delisted from one of the big boards doesn't mean it can't trade over the counter.  For example GM went OTC under the ticker MTLQQ for a while.  That being said, just because the stock is trading over the counter doesn't mean it has any real long term value. If the share is listed on a stock exchange that creates liquidity and orderly sales with specialist market makers, such as the NYSE, there will always be a counterparty to trade with, though they will let the price rise or fall to meet other open interest.  On other exchanges, or in closely held or private equity scenarios, this is not necessarily the case (NASDAQ has market maker firms that maintain the bid-ask spread and can do the same thing with their own inventory as the specialists, but are not required to by the brokerage rules as the NYSE brokers are).  The NYSE has listing requirements of at least 1.1 million shares, so there will not be a case with only 100 shares on this exchange. Your strategy of longing company(a) and shorting company(b) is flawed as the prices of company(a) and company(b) can both increase and though you are right , you will lose money due to the shorting strategy. You should not engage in pair trading , which is normally used for arbitrage purposes You should just buy company(a) since you believed its a better company compared to company(b) , its as simple as that I still can't understand why there is a price discrepancancy.  There isn't. It's the same stock and price differences between such major exchanges will always be minimal. I think you simply haven't paid attention to the date range. It seems Google finance only has data for FRA:BMW reaching back to 2011, so if you try to look at the development of your investment since 2009, you're not getting comparable data. Futures exchanges are essentially auction houses facilitating a two-way auction. While they provide a venue for buyers and sellers to come together and transact (be that a physical venue such as a pit at the CME or an electronic network such as Globex), they don't actively seek out or find buyers and sellers to pair them together. The exchanges enable this process through an order book. As a futures trader you may submit one of two types of order to an exchange: Market Order - this is sent to the exchange and is filled immediately by being paired with a limit order.   Limit Order - this is placed on the books of the exchange at the price you specify. If other participants enter opposing market orders at this price, then their market order will be paired with your limit order. In your example, trader B wishes to close his long position. To do this he may enter a market sell order, which will immediately close his position at the lowest possible buy limit price, or he may enter a limit sell order, specifying the price at or above which he is willing to sell. In the case of the limit order, he will only sell and successfully close his position if his order becomes the lowest sell order on the book. All this may be a lot easier to understand by looking at a visual image of an order book such as the one given in the explanation that I have published here: Stop Orders for Futures Finally, not that as far as the exchange is concerned, there is no difference between an order to open and an order to close a position. They're all just 'buy' or 'sell' orders. Whether they cause you to reduce/exit a position or increase/establish a position is relative to the position you currently hold; if you're flat a buy order establishes a new position, if you're short it closes your position and leaves you flat. "listed simultaneously in New York, London, and maybe even some Asian markets - is this correct? If the exchanges are not connected, then in primary market the shares are listed. On other exchanges, the ""Depository Receipts"" are listed. i.e. the Company will keep say 100,000 shares with the primary stock exchange / depository. Based on this it would create new instruments ""Depository Receipts"". They can be 1:1 or whatever ratio. hypothetically, if I want to buy all of the company's stock Even if it is on one exchange, buying all stocks would trigger various regulatory aspects of Companies Act, or Stock Exchange rules. This is not simple or easy like clicking some buttons and buying everything. That is, let's say that in New York the company has listed 1000 shares, and in London only 10 shares, each worth 10 USD Market capitalization is sum of all outstanding shares into value." "I mean, I'd say ""no shit"". The model is easy to reproduce (see the inverse model proposed by CHX and the new NYSE American), and people don't have a real incentive to trade there. IEX's main selling point to the buy side was the reduced price impact order router, which ultimately went away when they became an exchange.  Listings could be interesting, but I can't see why any company that doesn't have some sort of statement to make would want to list there versus the big two, or BATS. Hell, even BATS, a much more established market, has had a hard time drawing listings.  I'm glad they've seen a small bump in market share in the last few months, but I can't see them becoming one of the big three players any time soon (especially after having shat all over the industry during their launch period).  Side note: The UTP SIP (and soon the CTA SIP) are both **much** faster than when IEX went live. Turns out inside updates via the SIP are received faster than the prop market data feed, and faster than updates received over an order entry connection. Under these circumstances the street knows a trade occurred before the participants in the trade. This information asymmetry often results in market makers getting run the hell over, and makes them less likely to quote at the inside on your market." "Any shares you buy when a company is listed on one market will remain yours if the company moves to another market. Markets and exchanges like AIM are just venues for dealing in shares - indeed you can deal in those shares anywhere else that will allow you as well as on the AIM. The benefit of being listed in a market is that trade in the shares will be more ""liquid"" - there's more likely to be people who want to buy and sell them at any given time. The bigger concern would be what happens if the company does badly and drops out of the AIM entirely. You'd still be able to sell your shares to any willing buyer, but finding that buyer might get harder." "I guess there are accepted channels for this sort of thing, but I don't really understand why. Couldn't anyone sell them to anyone else at any time in any kind of market? I mean, if I had a friend who was talking the the IPO up, couldn't I have just said, ""Hey Fred, I'll sell you a Facebook share in two weeks time for thirty five bucks"" and be done with it?  Do exchanges provide legal services? Is there a law that says you have to go through them? And even if you *did* have to go through them, why wouldn't multiple exchanges list them instead of just one, and why wouldn't an exchange start listing them from the minute the gun fired (or before)?" Cross-listing shouldn't be an issue, as the sole reason stocks would behave differently on different exchanges would be due to exchange rates (sure, noise and time differences, but weekly data should take care most of that). If you're using MSCI World index figures in USD, you either have to convert stocks denominated in other currencies to USD at their historical fx rates, or just save a lot of time and use data from stocks listed in the US, when available. Investors who are themselves Canadian and already hold Canadian dollars (CAD) would be more likely to purchase the TSX-listed shares that are quoted in CAD, thus avoiding the currency exchange fees that would be required to buy USD-quoted shares listed on the NYSE. Assuming Shopify is only offering a single class of shares to the public in the IPO (and Shopify's form F-1 only mentions Class A subordinate voting shares as being offered) then the shares that will trade on the TSX and NYSE will be the same class, i.e. identical. Consequently, the primary difference will be the currency in which they are quoted and trade. This adds another dimension to possible arbitrage, where not only the bare price could deviate between exchanges, but also due to currency fluctuation. An additional implication for a company to maintain such a dual listing is that they'll need to adhere to the requirements of both the TSX and NYSE. While this may have a hard cost in terms of additional filing requirements etc., in theory they will benefit from the additional liquidity provided by having the multiple listings. Canadians, in particular, are more likely to invest in a Canadian company when it has a TSX listing quoted in CAD. Also, for a company listed on both the TSX and NYSE, I would expect the TSX listing would be more likely to yield inclusion in a significant market index—say, one based on market capitalization, and thus benefit the company by having its shares purchased by index ETFs and index mutual funds that track the index. I'll also remark that this dual U.S./Canadian exchange listing is not uncommon when it comes to Canadian companies that have significant business outside of Canada. I stumbled on the same discrepancy, and was puzzled by a significant difference between the two prices on ETR and FRA. For example, today is Sunday, and google shows the following closing prices for DAI. FRA:DAI: ETR:DAI: So it looks like there are indeed two different exchanges trading at different prices.  Now, the important value here, is the last column (Volume). According to Wikipedia, the trading on Frankfort Stock Exchange is done today exclusively via Xetra platform, thus the volume on ETR:DAI is much more important than on FRA:DAI.  Obviously, they Wikipedia is not 100% accurate, i.e. not all trading is done electronically via Xetra. According to their web-page, Frankfort exchange has a Specialist Trading on Frankfurt Floor service which has slightly different trading hours.  I suspect what Google and Yahoo show as Frankfort exchange is this manual trading via a Specialist (opposed to Xetra electronic trading). To answer your question, the stock you're having is exactly the same, meaning if you bought an ETR:BMW you can still sell it on FRA (by calling a FRA Trading Floor Specialist which will probably cost you a fee). On the other hand, for the portfolio valuation and performance assessments you should only use ETR:BMW prices, because it is way more liquid, and thus better reflect the current market valuation. "In the US there is only one stock market (ignoring penny stocks) and handfuls of different exchanges behind it.  NYSE and NASDAQ are two different exchanges, but all the products you can buy on one can also be bought on the other; i.e. they are all the same market.  So a US equities broker cannot possibly restrict access to any ""markets"" in the US because there is only one. (Interestingly, it is commonplace for US equity brokers to cheat their customers by using only exchanges where they -- the brokers -- get the best deals, even if it means your order is not executed as quickly or cheaply as possible.  This is called payment for order flow and unfortunately will probably take an Act of Congress to stop.) Some very large brokers will have trading access to popular equity markets in other countries (Toronto Stock Exchange, Mexico Stock Exchange, London Stock Exchange) and can support your trades there.  However, at many brokers or in less popular foreign markets this is usually not the case; to trade in the average foreign country you typically must open an account with a broker in that country." Reuters has a service you can subscribe to that will give you lots of Financial information that is not readily available in common feeds.  One of the things you can find is the listing/delist dates of stocks.  There are tools to build custom reports.  That would be a report you could write.  You can probably get the data for free through their rss feeds and on their website, but the custom reports is a paid feature. FWIW re-listing(listings that have been delisted but return to a status that they can be listed again) is pretty rare.  And I can not think of too many(any actually) penny stocks that have grown to be listed on a major exchange. "Trading on specific ECNs is the easy part - you simply specify the order routing in advance.  You are not buying or selling the *exact* same shares.  Shares are fungible - so if I simultaneously buy one share and sell another share, my net share position is zero - even if those trades don't settle until T+3.  PS ""The Nasdaq"" isn't really an exchange in the way that the CME, or other order-driven markets are.  It's really just a venue to bring market makers together.  It's almost like ""the internet,"" as in, when you buy something from Amazon, you're not buying it from ""the internet,"" but it was the internet that made your transaction with Amazon possible."