Or better, something like code + chart trading. For example if spy hits x point on a chart, liquidate all positions and reverse. I know interactive brokers lets you set buy and sells orders through a chart, are there any others?
NinjaTrader can do orders with a preset stop and reverse from it's Chart Trader. It works well if you want to slide your stop up or down in Chart Trader, but beware, if you all of a sudden decide to reverse by hitting the reverse button, it frequently drops your stop. You can download NinjaTrader for free and play with it using simulated trends.