I am new to Quantopian,and am need of a little bit of help. I am trying to create an algorithm that day trades stocks based on momentum. I have an equation that finds the difference between the current price and the price 12 minutes ago. It is my understanding that I can't use this factor in pipeline because pipeline is only called once a day. I want my algorithm to go long when the momentum value is .15 or greater, and sell the stock when the value drops below 0. I was able to create the momentum equation, but I am having trouble taking that value and using it to buy and sell stocks. Please Help.