I did an exchange of VTSAX for VFIAX on Monday for tax loss harvesting purposes. Unfortunately, I didn't think about the 30 days BEFORE component of the wash sale rules. Oops.
I used Specific ID for the cost basis for my sale. In the 30 days before the sale, I bought about 16 shares of VTSAX, $1,220 worth, in two different transactions. Both of these lots were sold as part of the exchange. Am I correct in thinking that if my total loss on the sale was $3,700, and the two lots that were purchased in the prior 30 days contributed to $300 of that loss, then my allowable loss is $3,400? (I understand that the max capital loss against ordinary income is $3K, I just overshot it a bit to ensure I didn't need to do another transaction to max my 2020 tax year TLH move, figuring I could carryforward any excess, or use it to offset and ST gains harvested later in the year.)
