@jtax wrote:
....(It would be a good idea to research if there is any guidance on what “substantially identical” means.)
It is unlikely that you will find anything, that has a significant bearing, directly from the IRS.
Pending mergers aside, it is rather clear that shares in two different corporations are not substantially identical, nor are two different actively managed mutual funds.
I believe the consensus, at least in the investment company, is to steer clear of buying/selling (within the wash sale rule period) index funds (passive) that are based on the same stock index but offered by different firms.
