@Tax2019Pay - when the 600 shares were sold, which lots were sold? which lots, if any, were remaining?
of the lots that were sold that made up the 600 shares, by rule, the lot with the oldest purchase date is the loss that is disallowed.
In your example, did you mean for there to be 500 shares purchased at the 1st brokerage but there to be 600 sales, that suggests thare more lots than what is in your example (or there is a hypothetical short sale???)
