Quote from damballa:
Thanks for the info. IQFeed asks $300 for api documentation. So I can only guess how it works. I guess it works by having some executable run in wine that opens local port and acts as a server? This would be ok for my case if you guys have not had problems communicating with the wine from native linux via tcp/ip.
That's correct. The messages are composed of a bunch of comma delimited fields. It's quite easy to deal with. I just used the diagnostics utility - Diasnostics.exe - to start the local IQFeed process and log on. You could probably automate this but it's not worth the bother.
Are nxcore feed and iqfeed the same? How much does IQfeed cost? From what I understand $300/year for api documentation and $63/month plus unknown exchange fees and unknown fee for level ii data ("also available as paid services..."). How much are you guys paying?
No they are not the same product. nxcore is much more expensive. Basic IQFeed gives you 500 symbols and a for a fee you can increase in increments of 500 to a limit of, I think, 1800. For $63 + $20 you get US stocks. Can't remember cost for various futures but it's reasonable. IQFeed is probably the cheapest way for you to get started and do some experimenting. I have read on the DTN message board that nxcore also works with wine, but I cannot confirm that.
As others here have pointed out, dealing with L2 data for a lot of symbols is non-trivial because of the huge amount of data. Best to start small with a few symbols, with the least expensive setup - possibly IQFeed. If after experimenting, you think it worthwhile, entirely rethink how you will deal with a large number of symbols.