My Portfolio holdings Inaccurate calculation of average cost, gain/loss
Error in formula for Average Cost per Share, which seems to occur If negative quantity lots (sales) exist for a holding.
Average looks OK for holdings with all purchases and no sales, but if any sales the calculated Average cost/share is way off, which makes the gain or loss figure inaccurate and useless for tracking investments in yahoo portfolio.
Example of 1 stock's inaccurate average- I have 12 lots of purchases at prices ranging from $14 to $17.87, and 4 lots of sales (quantity is minus) at prices from $14 to $16 .... and the automatic calculation of Average share cost is $18.01... more than I paid or received for any of the lots.
I see this error consistently for holdings having sale lots and can provide screenshots of detailed examples.