Suppose your broker charges $0.01 commission per share per trade (i.e. per side, and not round-trip). The exchange charges $0.041 per share per trade for removing liquidity and credits $0.030 per share per trade for adding liquidity. You want to run an electronic market-making strategy in a high-frequency setup. You post a below- market limit order (i.e. to add liquidity) to purchase 1,000 shares of a stock at $18.79 per share and your order is subsequently filled. (You get the credit.) If you buy and sell the share at the same price, what will be your net profit or loss per share in the roundtrip trade if you buy and sell by adding liquidity on both sides? $0.0390 $0.0400 $0.0410 $0.0420 $0.0430