I would like to understand the different charges and commissions charged by prop firms. I would like to know how commission works ? So if I buy 1000 shares of X at $1 and sell it at $1.5 My gain is 0.5 * 1000 = $500 Cost = $5 per 1000 shares So net profit = $ 495 ???? I buy 1000 shares of Y at $50 and sell it at $52 Gain = 2 * 1000 = $2000 Cost = $5 per 1000 shares So net profit = $ 1995 ??? Am I correct ? Other than $5 per 1000 shares what will I be charged I am just exploring the options of joining a prop trading firm in Chicago with a 10k capital contribution and 90-10 profit spilt.