, if someone holds 1btc from 2015 till date, how many btc will the person will be holding currently base on current Bitcoin values
You’re funny. If someone held 1 BTC since 2015, it’s still the same 1 BTC today. When you say “hold,” that means he didn’t sell or rebuy along the way.
So I don’t really see the sense of the question. Maybe what you actually want to ask is what the price was in 2015 and how much that same Bitcoin would be worth now, including the profit.
A very funny question, but I think it is a question that some people don't even know the answer to but really want to clarify by gaining an understanding. It still remains 1 BTC, but the only change is just the value. The 1 BTC we had 10 years ago is different from the 1 BTC we have right now. This has been a troubling question for most newbies; they think they need to invest 1 BTC before they can invest in Bitcoin, which 1 BTC can't be afforded by many people.
Beginners need to understand that when investing in Bitcoin for the long term, we don't look at the price of Bitcoin to invest; we consider what you can afford as an individual. The amount of Bitcoin you invest today can remain the same, but the values are different. That is why it is important to invest now to yield better value in the future.