I have done, using my own real money, algorithmic swing and day trading for many years. There are patterns that can be found and exploited, in the short term.

I have done, using my own real money, algorithmic swing and day trading for many years. There are patterns that can be found and exploited, in the short term. However, I was unable to predict changes in the trading environment. My software did not even try to watch the news. So when big macro events happen, like a civil war in Syria, for example, the patterns can change overnight, so I sometimes was left holding a heavy bag.