@roalddahl14 ,
I will break my answers into two different ones :
(a) Response to your PM there in ( although there I would need to know a little bit more as to the character of the warrant/option )
(b) a response here ( because it is of general interest )
Please see IRS U-Tube/ on-line "Show for the tax-pro". This provides a very good explanation of how to deal with "stocks/stock options " etc. received by an individual whom has worked both in the USA and abroad.
U.S. taxation of stock-based compensation received by nonresident aliens - YouTube video text script...
You can ignore the first three pages.
The examples here are quite instructive -- just turn it around as to NRA vs RA period.
This one also highlights the difference in the treatment of RSU/ISO and NQSO .
Hope this helps.
