To calculate the profit, use this formula:
Final price divided by the initial price multiple by the money invested minus the money invested.. Do not forget to apply bodmas.
If you invested $100 and the bitcoin increased from $40000 to $50000
50000 ÷ 40000 * 100 - 100
Profit = 125 - 100
=
$25If you invested $100 and the bitcoin decreased from $40000 to 30000
30000 ÷ 40000 * 100 - 100
Profit = 75 - 100
=
- $25If you invested $100 and the price of bitcoin increased from $40000 to $50000, you will gain $25, but if it decreased from $40000 to $30000, that means you lose $25. In this second case, you can continue to hold as the price will increase back, it can be long but the price will increase back, for bitcoin, not altcoins as many altcoins are disappointing.
4.Is COINBASE a exchange that you can get gains from or more so just where I buy coin?
You can buy and hold on noncustododial wallet and have full control over your crypto asset, not even advisable to hold on exchanges.