How do I write a stock trading algorithm?

If I want to have a trading platform to automatically trade a certain stock according to certain conditions, how would I do that?

Does a stock trading platforms have an area in it that one could place trading conditions that will CONTINUALLY trade til I stop it?

Public Comments

1. Of course! Trading platforms have different stopping rules that you can set up. For example, sell MMM stock if its price drops below 90 USD.

2. Hmm! This is a strange question.
1. I would say it is quite a complicated process that could be done.
2. If I could do it I would be selling the system for a lot of money

So logically, it is unlikely you will find anyone giving you algorithms etc. here!!

Basically data of all sorts (share prices, RNS announcements, volumes etc.) stream out of individual stock Exchanges. This raw data is purchased from them.
Then there are some proprietary websites that display this data and also have the facility for the user to input trades (with added parameters such as limits) and this information goes back to the stock exchange (via a market participant).
So that's the mechanics that you have to play with. Writing the algorithm and then a program should be relatively easy-if you haven't the skills then you will have to subcontract it. There may be a platform that is customisable. My memory seems to be saying something like MetaTrader--don't know whether it still exists.

3. Your question is interesting if you're asking whether or not one could write a stock trading algorithm. I think the answer is "ABSOLUTELY!" However, you'll want to learn the basics and even advanced trading techniques. I think ETrade has an exceptional and intuitive (as intuitive as math can be) interface in their Power Pro software, free when you sign up and make X number of trades per month. There's 100s of methods and millions of combos to choose from. So learn the basics first there. Then, if you conquer that, you can always start writing your own algorithm. I think it can be done esp if you're passionate about it. Obviously, you'll wan to pick the area in which you will specialize, be it equities (stocks), commodities, mutual funds, EFTs, ETFs, FOREX, etc. I'm guessing it would take about 20 years of study to get ALL of those down and then to write algorithms (stock picking and selling algorithsm) for each category. Quite an undertaking, but again, if you're a bright coder and love investing and learning about investing, this can totally be done. When you think about it, every variable that goes through every trader's mind and every decision he makes is PRECISELY an algorithm...albeit somewhat imperfect or inconsistent. Etrade has some really cool "CONDITIONAL ORDER TYPES" which, if you don't already know about, you might want to look into. Obviously you'll need to learn all about the various stops, limits and combinations thereof. Hope this little bit helps! Good luck for sure!