Stock market Datafeed

KenLong answered one year ago …

Chaos,

If you use TradeStation you can write your program using their system, fully automate it, and autotrade it.

I dont have TradeStation, so I dont know all the details. But I still know a bit.

They are expensive, unless you have a large account, or trade a lot. But everything I have read about them is great, and they are highly recomended by many profesionals.

They are the only ones I know of that are fully automated, so if you write your program on their system, it can access their data automaticaly, and auto trade the signals. They are the only system I know of with an autotrade feature. Every other brokerage requires you to get autotrade signals from a registered partner.
They have all the tools you need for testing and building mechanized systems, access to all the major markets and exchanges. One stop. They are the kings of mechanized , computerized trading.

Otherwise, you can use many different data sources. Unless your planing on running a real time system that signals trades during the day, theres no need for real time data. Plenty of good computerized systems run on EndOfDay data.

?How is your computer going to trade for you?

Unless your hooked to an autotrade system, as above, all it can do is signal trades for you to implement. If so, we're now down to a system that signals alerts based on your criteria. Many trading platforms and softwares can do this for you. Just thumb through a copy of Futures ,or Stocks and Commodities, magazine. There full of automated systems.

If you still want to write your own programs your going to have to decide how you want to access the data, not just where to get it, and there are several different ways.

EOD free data from Yahoo and other big providers. This is very slow and problematic. I have one program that does this, because I refuse to pay for their data, and it only works well late in the evening, and it constantly misses quotes.

Paid for data feeds from any of the big providers, such as E-Signal, and MetaStock are a little better. Many programers use this method and partner with E-Signal, or Metastock as their data providers.

Paid for data thats downloaded and accessed directly from your own computer. Worden Bros, TeleChart works this way. TeleChart downloads the data onto your computer, where it accesses it from. The updating of data is quick and can be done anytime during the day on a delayed basis. Since the data is stored on your computer your free to access it and use it at will.

I have this service, TeleChart is my primary charting tool. I also run OmniTrader from the Worden data.
OmniTrader simply accesses the TeleChart data files stored on my computer, and I choose which file to load. I can use any of the system files, such as, all stocks, all ETF's, all items in system, or component lists from the major indexes and ETF's. I can also access my own files and scans, so I can simply load one of my many watch lists, or my primary focus list, or the results from any scan I have writen.
This way I'm only looking for signals from within a filtered list of stocks that I know I'm interested in trading.

These are the major ways of getting data for your own programing or the programs you own. Have fun.

If you want more information on the process there are a lot of books out there. Check TradersLibrary or TradeStation itself, there are many books writen about creating your own computerized trading systems or using TradeStation software to create trading systems.