If you are trading on dolars, yes. You first calculate how much of that altcoin you can buy with the 2% of your capital and then calculate what price that amount of coins would need to have in order to be the 10% you wish.

If you are talking BTC, you should just do the same math; 2% at the price you can buy at that moment, and the price for said amount for it to reach your desired 10%

If you are talking in USD and trading BTC based on its value, you are going to loose money because of the volatility. 1 currency exchange might be risky, 2 at the same time is even riskier.

Putting this in numbers:

If you have 1000$ and want to invest a 2%; you take the price of the altcoin in dolars, and multiply it by the amount you are investing (20$). You then want to sell when the price of the coins you bought is 100$, so to know that, bought coin amount/100. If you are doing a BTC-Altcoin par, the same logic applies.

If you have btc and want to invest a % but based on its usd value, you first have to convert the BTC into USD, do the above math and hope the BTC price doesn't change much