This discussion of gains/loss record keeping seems to be the place to ask about a question I have. I'm writing an Access application to keep track of my trades to simplify future IRS reporting. Now that I've gotten to having to code for handling Stock Splits I discover I'm at a loss for how to establish a basis for the stock added. Assuming I've made multiple purchases and sales and have a residual number of shares remaining at the time of a split, how do I arrive at the basis for the new shares and for that matter, the old shares? I fear this will be a little more complicated than what it took to record buy and sell transactions because I simply record each event as a transaction. If I don't have enough shares entered as buys, my system won't let you sell them. Coming up with the equivalent of PRICE when the split transaction is recorded is obviously more difficult, not to mention having a mechanism that revises the basis for whatever original shares were in place.