Foreign investments in stocks

Hi I had some stocks worth less than $500 in a multinational(UK) bank. I was under the impression that this is not considered foreign investment as the same stocks are listed in NY stock exchange. Assuming this is foreign investment I have two questions,

I didn’t declare this in my application as the best of my knowledge it is not foreign investment because the value of the stocks are in dollars and the dividends are paid in dollars as well. But I declared my confusion about this by email after my interview to the investigator.

My second question is, does this be considered substantial? The whole investment is less than $500.

The SF86 states that if they are traded on US exchanges then they are not considered foreign investments. You don’t need to list them.