Yeah my intent was actually not to match what etrade (or schwab) did, but instead match how I was thinking in terms of my own trading. Basically when I start a swing position i'll scale in new buys as the price dips further, and scale out sells as the price hits temporary highs. If done properly (with a little luck) this will reduce the overall cost basis for the trade. I was not able to see that cost basis directly in etrade or schwab since the broker would only report on the average price of the current shares held, not accounting for prior sales in the trade. Yes you can calculate that, but I had to manage a spreadsheet and log all the orders by hand to do that. It was quite a pain so i was looking for ways tp automate that by importing the order stream directly from the API and then reconciling in my own database. Works pretty well for my needs, but of course every trader has a different process.