Effectively Connected Income

I have not researched this, but I do not see how it could be assuming this person did not perform any personal services in the US or owned or operated a business in the US that had an economic link to the stock in question. Even if there was an ordinary gain component on the sale (ordinarily taxed in the US as compensation) it would still not be ECI if the person did not perform any personal services in the US.

I see it as all investment income not ECI.

My understanding is that the person was working in the US, and the stock options were granted based on that work. I just didn't know if the capital gain from the eventual sale of that stock would be considered ECI. Sounds like you think, in this situation, it would be.

Thanks.

No, I don't. Once he bought the shares, it became an investment. Gain or loss on the sale of investment stock is not ECI.

Thanks. That was my thought, but I couldn't verify it.

If the options were granted at below market price, would the difference as of the grant date be ECI?