Financial data is now more accessible than ever via open APIs. This makes it easy to build Web or mobile applications that let you track your investment portfolio on a minute-by-minute basis (or at least as often as you care to check it). That’s the idea behind my new portfolio tracking application, which lets you create a virtual portfolio of stocks and then shows you the current market value at any given point.
How does it work? It’s mainly driven off the Quandl API, which is free to use and offers access to both open and premium financial databases. The Quandl API supports thousands of datasets, but I’m only using the free WIKI dataset, which is a community-curated list of end-of-day stock prices and dividends for 3,000 US companies.
The application itself is written in PHP using the Silex micro-framework and uses a hosted Cloudant instance for data storage. jQuery Mobile ensures that the interface works well on smartphones, and the entire thing is hosted on Bluemix for maximum scalability. There’s also a little bit of HybridAuth in the mix, just so that every user can create his or her own account in the system using existing Google credentials.