This might be a very easy thing but still
For example:
The price rises from $2500 to $3000, this in an increase of 1.15%.
So should I do 1.15*(the bitcoin amount I have now at the price of 2500) ?
If you had 2500 usd and bought 1 btc and btc price increased to 3000 usd. Then your USD balance increased 20%.
I advise you to use an application like blockfolio to monitor your holdings.