주식을 당해 10k 를 사고 당해에 매도하지 않은경우 세금 혜택은 없고 매도한 년도에 차액에 대해서만 세금을 내는건가요?

Year 1. you buy 10k worth of stocks.
Year 1.5 it becomes 5k (no deduction unless you sell it at lose)
Year 2 it becomes 15k
Year 3 you sell at 20k
you need to pay tax on 20k(you earn) – 10k(you spnt) = 10k