Which stock trading firms do you use? Most I've seen are 5-10$ per trade and small % for currency exchange transactions. Paying 10-15% for a stock trade could e

Which stock trading firms do you use? Most I've seen are 5-10$ per trade and small % for currency exchange transactions. Paying 10-15% for a stock trade could easily cost $10s of 1000 in commisions which is clearly not the case. Also for small trading Robinhood has free trades.