Automatic Trading?

I'm a complete noob, so if there's a more appropriate subreddit, please point me in the right direction.

I'm a software developer, and someone approached me about building a software suite that monitors real time pricing data for a specific trend. When this trend is noticed, the software would automatically buy/sell.

Questions:

1. Is automatic trading like that a thing? Is it allowed on all exchanges?

2. From my first pass research effort, it looks like something similar to TradeStation might already accomplish want he wants. Anyone used TradeStation? (http://ift.tt/2jOl0ew)

3. Lastly, it seems the smallest barrier of entry API for getting real time data is Intrino - Fintech. Can anyone comment on their API?

Thanks guys!

Submitted January 22, 2017 at 07:35PM by CastleSeven http://ift.tt/2jGLfBP