Company stock listed in multiple exchanges?
If a company's shares trade in multiple exchanges, the prices in every exchange are very near to each other, otherwise you could earn money by doing arbitrage deals (buying in one, selling in the other) - and people do that once it becomes worth it. Which stock exchange you use is more a convenience for the buyer/seller - many investment banks offer only something local/near, and you have to go to specific investment banks to use other exchanges. For example, in Germany, it is easy to deal in Frankfurt, but if you want to trade at the the NASDAQ, you have to run around and find a bank that offers it, and you probably have to pay extra for it. In the USA, most investment banks offer NASDAQ, but if you want to trade in Frankfurt, you will have run around for an international company that offers that. As a stock owner/buyer, you can sell/buy your shares on any stock exchange where the company is listed (again, assuming your investment broker supports it). So you can buy in Frankfurt and sell in Tokyo seconds later, as nothing needs to be physically moved. Companies that are listed in multiple stock exchangs are typically large, and offer this to make trading their shares easier for a larger part of the world. Considering your 'theoretical buy all shares' - the shares are not located in the exchanges, they are in the hands of the owners, and not all are for sale, for various reasons. The owners decide if and when they want them offered for sale, and they also decide which stock exchange they offer them on; so you would need to go to all exchanges to buy them all. However, if you raise your offer price in one exchange only slightly, someone will see the arbitrage and buy them in the other locations and offer them to you in your stock exchange; in other words, for a small fee the shares will come to you. But again, most shares are typically not for sale. It's the same as trying to buy all Chevy Tahoes - even if you had the money, most owners wouldn't know or care about you. You would have to go around and contact every single one and convince them to sell. It doesn't matter which exchange a share was purchased through (or if it was even purchased on an exchange at all--physical share certificates can be bought and sold outside of any exchange). A share is a share, and any share available for purchase in New York is available to be purchased in London. Buying all of a company's stock is not something that can generally be done through the stock market. The practical way to accomplish buying a company out is to purchase a controlling interest, or enough shares to have enough votes to bind the board to a specific course of action. Then vote to sell all outstanding shares to another company at a particular fixed price per share. Market capitalization is an inaccurate measure of the size of a company in the first place, but if you want to quantify it, you can take the number of outstanding shares (anywhere and everywhere) and multiply them by the price on any of the exchanges that sell it. That will give you the market capitalization in the currency that is used by whatever exchange you chose. Keep in mind that the exchanges do not hold, buy, or sell the stock - people (or funds) do.  All the exchange does is facilitate the sale of stock from one entity to another. So the shares outstanding (and market cap) for a company are set regardless of how many exchanges the stock is listed on.  The company typically indicates the number of shares outstanding in its financial statements.  I do not know if the exchange itself keeps track of shares outstanding; it may just report whatever the company publishes. So theoretically, if you wanted to buy all of the stock of a company, you could do it all in one exchange, provided that all the existing holders of the stock were willing to sell you their shares.  There are many issues with that, though, which I don't think are germane to your question. "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."
Different exchanges sometimes offer different order types, and of course have different trading fees.  But once a trade is finished, it should not matter where it was executed. I'll give it a shot, even though you don't seem to be responding to my comment. SIPC insures against fraud or abuse of its members. If you purchased a stock through a SIPC member broker and it was held in trust by a SIPC member, you're covered by its protection. Where you purchased the stock - doesn't matter. There are however things SIPC doesn't cover. That said, SIPC members are SEC-registred brokers, i.e.: brokers operating in the USA. If you're buying on the UK stock exchange - you need to check that you're still operating through a US SIPC member. As I mentioned in the comment - the specific company that you mentioned has different entities for the US operations and the UK operations. Buying through them on LSE is likely to bind you with their UK entity that is not SIPC member. You'll have to check that directly with them. "Exchange A has 100 shares of a stock at $10, the next 100 shares cost $10.01. Exchange B has the same pricing structure.  A fund manager wants to buy 200 shares of the stock, and decides that buying 100 shares at $10 from each exchange will be cheaper than staying in one exchange and paying $10.01 for the second half of his order.  The manager places two separate orders. Let's say the first order reaches exchange A, and the trade executes at $10. Traders (algorithms) on exchange B see this happen, and adjust their price up to $10.01 accordingly. Now, when the manager's order reaches exchange B, there will no longer be any shares trading at $10.  Some people say that this is front running, but if the manager only wanted 100 shares, the price would have still shifted. Some say this creates a more efficient market with tighter spreads due to the decreased risk to the market maker, but it also means the aggregate bid-ask offers across multiple exchanges are not necessarily accurate, creating a ""false liquidity"". You can decide for yourself whether or not this is a good thing." Yes, this can and does certainly happen. When two companies each own stock in each other, it's called a cross holding. I learned about cross holdings in reference to Japanese companies (see Wikipedia - Keiretsu) but the phenomenon is certainly not exclusive to that jurisdiction.  Here are a few additional references: If you check out China Stock Markets Web provides details on all things that trade on there. It covers the Hang Seng Index, SSE Index, and SSE Component Index. There is also tons of information for investors on the exchange website here. A stock market is just that, a market place where buyers and sellers come together to buy and sell shares in companies listed on that stock market. There is no global stock price, the price relates to the last price a stock was traded at on a particular stock market. However, a company can be listed on more than one stock exchange. For example, some Australian companies are listed both on the Australian Stock Exchange (ASX) and the NYSE, and they usually trade at different prices on the different exchanges. Also, there is no formula to determine a stock price. In your example where C wants to buy at 110 and B wants to sell at 120, there will be no sale until one or both of them decides to change their bid or offer to match the opposite, or until new buyers and/or sellers come into the market closing the gap between the buy and sell prices and creating more liquidity. It is all to do with supply and demand and peoples' emotions. "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""." "Google Finance certainly has data for Tokyo Stock Exchange (called TYO on Google) listings.  You could create a ""portfolio"" consisting of the stocks you care about and then visit it once per day (or write a script to do so)." Try Google Finance Screener ; you will be able to filter for NASDAQ and NYSE exchanges. http://mobile.nytimes.com/blogs/economix/2014/04/02/the-many-classes-of-google-stock/ Are you counting both class A and other share classes? how does the trading company know which one I want to sell? It doesn't need to know. You just sell one. From taxation point of view depending on the country / tax jurisdiction, it can be only be FIFO or specific stock. Also important to keep in mind is the difference in liquidity. The stock could be very liquid in 1 exchange but not in another. When times get bad, liquidity could dry up 1 one exchange, which results in a trading discount. "You cannot determine this solely by the ticker length. However, there are some conventions that may help steer you there. Nasdaq has 2-4 base letters BATS has 4 base letters NYSE equity securities have 1-4 base letters. NYSE Mkt (formerly Amex) have 1-4 base letters. NYSE Arca has 4 base letters OTC has 4 base letters. Security types other than equities may have additional letters added, and each exchange (and data vendors) have different conventions for how this is handled. So if you see ""T"" for a US-listed security it would be only be either NASDAQ, NYSE or NYSE Mkt. If you see ""ANET"" then you cannot tell which exchange it is listed on.  (In this case, ANET Arista Networks is actually a NYSE stock). For some non-equity security types, such as hybrids, and debt instruments, some exchanges add ""P"" to the end for ""preferreds"" (Nasdaq and OTC) and NYSE/NYSE Mkt have a variety of methods (including not adding anything) to the ticker.  Examples include NYSE:TFG, NYSEMkt:IPB, Nasdaaq: AGNCP, Nasdaq:OXLCN.  It all becomes rather confusing given the changes in conventions over the years. Essentially, you require data that provides you with ticker, listing location and security type. The exchanges allocate security tickers in conjunction with the SEC so there are no overlaps.  eg. The same ticker cannot represent two different securities. However, tickers can be re-used.  For example, the ticker AB has been used by the following companies:" According to this page on their website (http://www.kotaksecurities.com/internationaleq/homepage.htm), Kotak Securities is one big-name Indian broker that offers an international equities account to its Indian customers.  Presumably, they should be able to answer all your questions. Since this is a competitive market, one can assume that others like ICICI Direct must also be doing so. Say a stock is listed in Nasdaq, and the same company has a stock listed in Tsx. Does the Nasdaq price affect the Tsx price as trading commences? Not directly. Basically, an exchange is a market, and the price is defined only by supply and demand in that market. However, any substantial price differential for a commodity traded in multiple market creates an arbitrage opportunity, and there are many traders whose job it is exactly to find and use such opportunities. Their activity in turn has the effect of reducing the price differentials to the point where transaction costs make them unprofitable. With high-frequency traders around, the time for a price differential to disappear is nowadays measured in milliseconds. If a trader buys from one exchange, will it affect the price of the other? Only through the mechanism mentioned above.  Are there any benefits to being listed in two exchanges? It increases the liquidity of a stock.