Then the remaining total loss is pro-rata on a share basis versus the 100 Replacement shares to determine your
Wash Sale, adjustment, and basis and date change on the 100 shares.

I reply:

Not necessarily. You must also use FIFO accounting to determine which losses are disallowed if the sale of more than 100
shares (the number of replacement shares purchased) resulted in a loss. For example, suppose you had three separate
purchases of 50 shares each, all of which resulted in losses of various sizes (because they were purchased at different
prices), together with another purchase of 80 shares that resulted in a gain. Then the loss on the two earlier 50-share lots is
disallowed, but the loss on the final 50-share lot is realized in full. You do NOT take disallow two-thirds of the entire loss
due to the wash sale rule, you disallow the loss on two-thirds of the shares, which may well be different. --Bob

I stand corrected, you're right Bob. I presume you agree with the other part of my post? ed