Explain why the bid-ask spread is a transaction cost. (select from the drop-down menus.)investors always buy at the 1. (ask/bid) and sell at the 2. (ask/bid). since 3. (ask/bid) prices always exceed 4. (bid/ask) prices, investors "5. (lose/gain)" this difference. it is one of the transaction costs. since the market makers take the other side of the trade, they make this difference.