it will be the 1st 100 of the 200 that you sell. however, if these are sold at a loss and within 31 days of this sale you purchase 100 shares of the identical security, you'll have another wash sale.
now here's is what the IRS allows
https://www.irs.gov/faqs/capital-gains-losses-and-sale-of-home/stocks-options-splits-traders/stocks-...
Question
How do I figure the cost basis when the shares I'm selling were purchased at various times and at different prices?
Answer
The basis of stocks or bonds you own generally is the purchase price plus the costs of purchase, such as commissions and recording or transfer fees. When selling securities, you should be able to identify the specific shares you are selling.
If you can identify which shares of stock you sold, your basis generally is:
What you paid for the shares sold plus any costs of purchase.
If you can't adequately identify the shares you sold and you bought the shares at various times for different prices, the basis of the stock sold is:
The basis of the shares you acquired first, then the basis of the stock later acquired, and so forth (first-in first-out). Except for certain mutual fund shares and certain dividend reinvestment plans, you can't use the average basis per share to figure gain or loss on the sale of stock.
so if you want to dispose of these specific wash sale shares (when you hold shares acquired at an earlier date) you must inform the broker that you want to sell 100 shares from the lot purchased on ........
otherwise, the broker will use the fifo basis
on other thing is that when there is a wash sale the holding period tacks on
example 100 shares purchased 10/30/2020
100 shares sold 10/25/2021 at a loss - short term loss
100 shares purchased 11/15/2021 wash sale resulting in disallowance of ST loss of shares sold on 10/25/2021
100 shares sold 11/30/2021 the holding period from 10/30/2020 resulting in long term gain or loss
provided if a loss 100 shares of identical security not purchase within 31 days
this is just an FYI since the broker will handle it correctly.
