In yesterday’s post about all my Amazon orders, JonathanC posted an interesting comment: “How about this one as a Power BI challenge: current value of the portfolio if you had purchased stock of Amazon instead of the product.” … Challenge accepted!
I already had a list of all my Amazon orders. I think headed to Yahoo Finance and downloaded a daily history of Amazon stock stretching back to 2001 when I made my first product purchase. That came as a CSV file too. Both files got loaded into Power Query. I did a merge on the date column, removed the columns that I didn’t need, and added a custom column that was the money spent divided by the closing share price that day. That told me how many shares I could have purchased. A quick sum over that column divided by a sum of the money spent revealed that I would have made an 81% return on my money! But wait a minute, transactions aren’t free. If I was pay $8 per transaction then I would have only made a 37% return. But that’s silly since I probably wouldn’t have bought $10 of stock at a time like I do with Amazon orders.