Find out the difference between two stocks of the same company (how to identify ADRs, etc)
Generally, when I run across this kind of situation, I look for the Investor Relations section of the corporate website for a 'Stock Information' (or similar) tab or link.   This usually contains information explaining the different shares classes, how they relate (if at all), voting and/or dividend rights, and taxation differences for the different classes. However, I have trouble finding such a page on a central BYD corporate investor relations page.   I did find this page detailing the HK1211 shares: http://www.byd.com/investor/base_information.html.  I don't know what or why, but something tells me this is an older page. Searching on, I also found this page which looks newer and clarifies that the difference you are seeing is between 'A' and 'H' shares. http://www.byd.cn/BYDEnglish/basic/article.jsp?articleId=1524676.  (I'm guessing but I'd think somewhere in the announcements on this byd.cn site, you may find more details of any structural differences between share classes -- I just didn't want to page through them all.)
"In the US, stocks are listed on one exchange but can be traded on multiple venues.  You need to confirm exactly what your data is showing: a) trades on the primary-listed exchange; or b) trades made at any venue. Also, the trade condition codes are important.  Only certain trade condition codes contribute towards the day's open/high/low/close and some others only contribute towards the volume data.  The Consolidated Tape Association is very clear on which trades should contribute towards each value - but some vendors have their own interpretation (or just simply an erroneous interpretation of the specifications). It may surprise you to find that the majority of trading volume for many stocks is not on their primary-listed exchange.  For example, on 2 Mar 2015, NASDAQ:AAPL traded a total volume across all venues was 48096663 shares but trading on NASDAQ itself was 12050277 shares. Trades can be cancelled.  Some data vendors do not modify their data to reflect these busted trades.   Some data vendors also ""snapshot"" their feed at a particular point in time of the data.  Some exchanges can provide data (mainly corrections) 4-5 hours after the closing bell.  By snapshotting the data too early and throwing away any subsequent data is a typical cause of data discrepancies.   Some data vendors also round prices/volumes - but stocks don't just trade to two decimal places. So you may well be comparing two different sets of trades (with their own specific inclusion rules) against the same stock.  You need to confirm with your data sources exactly how they do things. Disclosure: Premium Data is an end-of-day daily data vendor." The quotes on JSE are for 100 share lots.  The quotes on NYSE are for single shares.  That still leaves some price difference, but much less than you calculated. (EDIT: Equivalently, the price is quoted in 1/100th of a Rand.  The Reuter's listing makes this explicit since the price is listed as ZAc rather than ZAR.  http://www.reuters.com/finance/stocks/overview?symbol=HARJ.J) As noted in the other answer currently up, NYSE is quoting American Depositary Receipts (ADRs) for this company, which is not directly its stock.  The ADR in this case, if you check the prospectus, is currently 1 share of the ADR = 1 share of the stock on its home market.  A US institution (in this case it looks like BNY Mellon) is holding shares of stock to back each ADR. Arbitrage is possible and does happen.  It's not perfect though, because there are a variety of other cost and risk factors that need to be considered.  There's a good review here: Report by JP Morgan Some summary points: Some ADRs have standardized options that trade on US exchanges.  If your stock/ADR is one of those, then you find the put option through most brokerages that deal with stock options and trade the option like you would on a regular stock.  If your ADR does not have standardized options, then your options will depend on where the ADR trades.  If it's OTC, you might not even be able to short it.  If it trades on a major exchange, the shorting the ADR may be a viable choice. Assuming the data you're referring to is this line: the difference might be related to the different exchanges on which the stock trades.  FINRA could be listing the reported volume from one exchange, while the NASDAQ data might be listing the volume on all exchanges. This is an important distinction because AAV is a Canadian company that is listed on the Toronto Stock Exchange and the NYSE. The Q at the end of the line stands for NASDAQ, according to FINRA's codebook for those data. My guess is that the FINRA data is only reporting the volume for the NASDAQ exchange and not the total volume for all exchanges (Toronto, NASDAQ, NYSE, etc.) while the data straight from NASDAQ, oddly enough, is reporting the total volume. However, FINRA could also face reporting discrepancies, since it's a regulatory body and therefore might not have the most up-to-date volume data that the various exchanges can access.  I don't know if it's related or not, but looking at the NASDAQ historical data, it looks like the volume on March 6, the day you're asking about, was much lower than the volume in most of the days immediately before or after it. For all I know, something might have happened that day concerning that particular stock or the market as a whole. I don't remember anything in particular, but you never know. Liquidity on dual listed equities is rarely the same on both exchanges. More liquidity means you would typically get a better price assuming you execute the trades using the same order types. It's recommended to trade where the liquidity is greater unless your trading method benefits somehow from it being lower. It's important to remember that some ADRs (some European companies listed in US) have ADR fees which vary. USD/EUR transaction fees are low when using a decent broker but you're obviously participating in the currency risk. First and foremost you need to be aware of what you are comparing. In this case, HSBC as traded on the NYSE exchange is not common shares, but an ADR (American Depository Receipt) with a 5:1 ratio from the actual shares. So for most intents and purposes owning one ADR is like owning five common shares. But for special events like dividends, there may be other considerations, such as the depository bank (the institution that created the ADR) may take a percentage. Further, given that some people, accounts or institutions may be required to invest in a given country or not, there may be some permanent price dislocation between the shares and the ADR, which can further lead to discrepancies which are then highlighted by the seeming difference in dividends. "(Note: out of my depth here, but in case this helps...) While not a direct answer to your question, I'll point out that in the inverse situation - a U.S. investor who wants to buy individual stocks of companies headquartered outside US - you would buy ADRs, which are $-denominated ""wrapper"" stocks.  They can be listed with one or multiple brokerages. One alternative I'd offer the person in my example would be, ""Are you really sure you want to directly buy individual stocks?""  One less targeted approach available in the US is to buy ETFs targeted for a given country (or region).   Maybe there's something similar there in Asia that would eliminate the (somewhat) higher fees associated with trading foreign stocks." I have not looked in details but apparently the company has (at least) a dual listing in Hong Kong (its main listing, ticker 700) and in the US (ticker TCTZF). It also has an ADR (TCEHY), the underlying of which is the HK line. The two US listings essentially trade at the same price and will provide very similar returns but a major difference is that TCTZF pays dividends in HKD whereas TCEHY pays its dividends in USD. The latter may be more convenient depending on the account you use to trade the stock. The ADR line is also more liquid. 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. Something like cost = a × avg_spreadb + c × volatilityd × (order_size/avg_volume)e. Different brokers have different formulas, and different trading patterns will have different coefficients. "You could not have two stocks both at $40, both with P/E 2, but one an EPS of $5 and the other $10.  EPS = Earnings Per Share P/E = Price per share/Earnings Per Share So, in your example, the stock with EPS of $5 has a P/E of 8, and the stock with an EPS of $10 has a P/E of 4.  So no, it's not valid way of looking at things, because your understanding of EPS and P/E is incorrect. Update: Ok, with that fixed, I think I understand your question better. This isn't a valid way of looking at P/E. You nailed one problem yourself at the end of the post: The tricky part is that you have to assume certain values remain   constant, I suppose But besides that, it still doesn't work. It seems to make sense in the context of investor psychology: if a stock is ""supposed to"" trade at a low P/E, like a utility, that it would stay at that low P/E, and thus a $1 worth of EPS increase would result in lower $$ price increase than a stock that was ""supposed to"" have a high P/E. And that would be true. But let's game it out: Scenario Say you have two stocks, ABC and XYZ. Both have $5 EPS. ABC is a utility, so it has a low P/E of 5, and thus trades at $25/share. XYZ is a high flying tech company, so it has a P/E of 10, thus trading at $50/share. If both companies increase their EPS by $1, to $6, and the P/Es remain the same, that means company ABC rises to $30, and company XYZ rises to $60. Hey! One went up $5, and the other $10, twice as much! That means XYZ was the better investment, right? Nope. You see, shares are not tokens, and you don't get an identical, arbitrary number of them. You make an investment, and that's in dollars. So, say you'd invested $1,000 in each. $1,000 in ABC buys you 40 shares. $1,000 in XYZ buys you 20 shares. Their EPS adds that buck, the shares rise to maintain P/E, and you have: ABC: $6 EPS at P/E 5 = $30/share. Position value = 40 shares x $30/share = $1,200 XYZ: $6 EPS at P/E 10 = $60/share. Position value = 20 shares x $60/share = $1,200 They both make you the exact same 20% profit. It makes sense when you think about it this way: a 20% increase in EPS is going to give you a 20% increase in price if the P/E is to remain constant. It doesn't matter what the dollar amount of the EPS or the share price is." "There are basically two different markets for ADRs and ordinary shares. 1) The American market, 2) the ""local"" market. The following is not true for most stocks in ""developed"" markets. But it is often true that the American market (for ADRs) is far more liquid than the local market for ordinary shares of a developing country. For instance, there was a time when the ADRs of Telmex (Telefonos of Mexico) was the fifth most traded stock in the world, after Exxon (before its merger with Mobil), IBM, Microsoft, and A T&T, meaning that it was easy to trade with low fees on the NYSE. It was much harder and slower to buy the local shares of Telmex in Mexico, on the Mexican exchange. Also, the accompanying currency transactions were harder to execute with the ord, because you have to settle in local currency and pay an FX commission. With the ADR, the exchange rate is ""built"" into the (dollar) price, and you settle in dollars." I'm a bit out of my element here, but my guess is the right way to think about this is: knowing what you do now about the underlying company (NZT), pretend they  had never offered ADR shares.  Would you buy their foreign listed shares today? Another way of looking at it would be: would you know how to sell the foreign-listed shares today if you had to do so in an emergency?   If not, I'd also push gently in the direction of selling sooner than later. "It's easy to own many of the larger UK stocks. Companies like British Petroleum, Glaxo, and Royal Dutch Shell, list what they call ADRs (American Depositary Receipts) on the U.S. stock exchanges. That is, they will deposit local shares with Bank of NY Mellon, JP Morgan Chase, or Citicorp (the three banks that do this type of business), and the banks will turn around and issue ADRs equivalent to the number of shares on deposit. This is not true with ""small cap"" companies. In those cases, a broker like Schwab may occasionally help you, usually not. But you might have difficulty trading U.S. small cap companies as well." 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.