How do I find the mappings between sedol and isin codes?
There is a relatively straightforward transformation explained on the Wikipedia page here and on the links from that page.  Note that this only applies to SEDOLs for instruments listed on the London Stock Exchange (LSE). To convert SEDOL to ISIN you pad leading zeroes onto the SEDOL until you have 9 digits.  Then you add the two letter country code (as defined in ISO 3166-1) to the front.  Then you add a final checksum digit to the end, again as defined in the algorithm on the Wikipedia page. To convert ISIN to SEDOL you do the reverse: remove the final digit, remove the two leading letters, and strip off any leading zeroes. Example: You can get this information through Bloomberg, but it's a paid service.
"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." "That's not what he meant to say.  He meant that beyond ""browsing internet"", you need to know math, how to write and compose long essays and reports, work ethics, business principles, and simple general knowledge... and many young millennials are terrible in math, can't write proper English, no work ethics, conviction, principal, or even aspiration to build career, let alone understand business and general knowledge. They can't even find Alaska in the map." Why does Apple have to do their own maps app anyway? You don't have to keep everything in house. Google and other nav companies have already spent a ton of money and resources creating fantastic navigation maps. Why not just license their work and slap your own UI over it and call it a day? R has really good package that lets you calculate the return of rebalanced portfolios. The package is called: PerformanceAnalytics (see: http://www.inside-r.org/packages/cran/PerformanceAnalytics/docs/Return.portfolio). I quickly wrote a small script for you that lets you do exactly what you want.  Code: By default the portfolio is rebalanced to an equally weighted portfolio. It is also possible to rebalance your portfolio using custom weights. See the documentation on how to do this.  In order for this code to work you need to have your data already in return terms. You can do this easily in Excel. Make sure your data in excel looks like this: Than export your data to a CSV file. Note: before you run the code make sure you have installed the package PerformanceAnalytics. You can do this as follows:  Let me know if you have any questions regarding the above. "Hey there - thanks for your input. The internet can be a confusing place sometimes, especially when you don't know what to look for. I've subscribed to usenet (for the ""white papers"") but so far to no avail. I'll definitely search for the Moody's paper!" Here is a list of threads in other subreddits about the same content:   * [What does the circular economy look like in cities?](https://www.reddit.com/r/environment/comments/71nlz0/what_does_the_circular_economy_look_like_in_cities/) on /r/environment with 0 karma (created at 2017-09-22 04:55:20 by /u/thinkB4WeSpeak)  ----   ^^I ^^am ^^a ^^bot  ^^[FAQ](https://www.reddit.com/r/DuplicatesBot/wiki/index)-[Code](https://github.com/PokestarFan/DuplicateBot)-[Bugs](https://www.reddit.com/r/DuplicatesBot/comments/6ypgmx/bugs_and_problems/)-[Suggestions](https://www.reddit.com/r/DuplicatesBot/comments/6ypg85/suggestion_for_duplicatesbot/)-[Block](https://www.reddit.com/r/DuplicatesBot/wiki/index#wiki_block_bot_from_tagging_on_your_posts)  ^^Now ^^you ^^can ^^remove ^^the ^^comment ^^by ^^replying ^^delete! You should be careful to pick the Ferro Silicon Import Data, as only the genuine data will support your business. You get access any information related to import trade and the information includes HS code, Product Description, Bill of Loading, Quantity, Country Name, Port Name etc. set up a US company (WY is cheap and easy), go south and open a personal and business bank account, ask for the itin form. file for the itin. set up your EIN for the company. get a credit card for both. pay some mail forwarding service with it. file for taxes in the next year using your itin. prepaid cards do not link to your tax id