Sure, Quantopian is nice. But it's only stock data in some cases. It is up-to-date. It serves well for back-testing and for managing a portfolio in a certain wa

Sure, Quantopian is nice. But it's only stock data in some cases. It is up-to-date. It serves well for back-testing and for managing a portfolio in a certain way using newer ideas, but real-time investing information is limited. Quandl is nice, but it is only "shared data" that people are willing to submit so it is not up-to-date. It does have the best API of the group because you can pull data from it with very few lines of code, or simply download a .csv. Thinknum is nice, they do discounted cash flow computing which is useful for investing. But theres not much there besides the balance sheets. It is a large amount of data, but it's not curated in a very digestable format. If you look at finviz you can see what I mean about more digestable information. It has green or red marks where it lists information indicating if things are good or bad that is a bit more digestable. Mutual fund inflows are what really do a lot of the work for the market, but many financial sites do not cover this data. And momentum investing seems to be very big, but it's not covered that much.