I have an account where the client buys and sells Euros and Dollars on a regular basis. This would be simple enough to track except I have to keep track of the original inventories exchange rate. Let's say an original purchase of 100,000 Euros is at 1.5% (to the Dollar). The client then purchases 100,000 more Euros at 2%. Then decides to sell 150,000 Euros. The original 100,000 is exhausted and I have to apply the basis rate of 1.5% to it, and 2% to the remaining 50,000 Euros of the total 150,000 Euros sold. Is there a formula that can help keep track of original inventories so I can just put the amount in and it totals automatically, knowing the original basis rate so it accurately reflects the profit off of the 1.5% of the original 100,000 Euros, and 2% of the 50,000? This is further complicated by the fact that the client not only makes several transactions a month, but that they buy and sell both Dollars and Euros. It's such a headache to try to keep track of original inventories that I would be willing to donate a body part just to get a spreadsheet built for this. I have thus far been unsuccessful finding one or a formula that simplifies this process... Can Anyone Help?