IB has a wide variety of data feeds, some free, most for fee. However, the fees are very low IMO, e.g. $1-3/month. I think they only pass on charges from the data vendors, without a markup.
They also have a very wide range of methods for defining or automating trades, and I don't think you'll find cheaper trading fees or margin rates anywhere else. Some of the methods for posting a bid or ask helps market makers, which pay a little to encourage those types, you can actually earn a tiny amount on trades instead of paying.
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