The current price of Bitcoin as of the time of writing this post is $26,600, and as such, it clearly means that if a user had bought 1BTC when the value was $60k, what he/she should be having now is $26,600 and not $0, because that's not possible, Bitcoin is not altcoin or shitcoin that goes $0 in value, which is why it is the most invested cryptocurrency, and the coin with the largest market cap.

Moreover, here are some examples to help you understand how this works.

QUESTION:
Mr. A invested $200 in Bitcoin when the price of BTC was $60k/BTC, and kept hodling the coin till the value fell to $26k/BTC, so how much do you think should be left in his wallet currently?

Answer:
To know the percentage of $26k to $60k, what you need to do is;
$26,000/$60,000×100%= 43.3%

To know percentage lost = 100% - 43.3% = 56.7%

Therefore, to know how much lost;
56.7/100%×$200= $113.4

Hence; how much that will be left in the users account will be$200- $113.4 = $86.6