Many traders follow a simple rule: never lose more than 1% to 2% of the account on one trade. With a $5,000 account and a 1% rule, a losing trade costs at most $50.
From risk to position size
Your stop-loss decides how much you can buy. If you enter at $2,500 with a stop at $2,400, each coin can lose $100. To lose at most $50, you buy 0.5 coins, a $1,250 position.
Ten losing trades in a row at 1% each leaves you with about 90% of your account. At 10% per trade, you would have about a third left.
Before you enter, check the possible reward with the crypto profit calculator so the trade is worth the risk. This is general education, not financial advice.