Question: Is a foreign exchange loss not realized unless I exchange dollars for won right now?

‌It isn't a realized loss, right?
I bought 1 dollar when the rate was 1,490 KRW per dollar.
Even if the rate later drops to 1,390 KRW per dollar,
as long as I don't exchange my dollars back into won,
there isn't an actual loss yet, is there?
Stock market newbie
This is quite difficult ㅜ ㅜ