NO.PZ2022061307000013
问题如下：
Question A trader places a limit order to buy shares at a price of $49.94 with the stock trading at a market bid price of $49.49 and the bid–ask spread of 0.7%. The order will most likely be filled at:选项：
A.$49.94. B.$49.84. C.$49.49.解释：
SolutionB is correct. An order is filled at the best available price as long as this price is lower than the limit price. In this case, the best available price is the market ask price = $49.49 × (1 + 0.7%) = $49.84. Because this price is lower than the limit price of $49.94, the order will be filled at this price.
A is incorrect. The order limit of $49.94 is larger than the market ask price and accordingly the order will be filled at the market ask price (i.e., $49.84) and not the limit order price.
C is incorrect. The trader can only sell (not buy) at the market bid price. He has to buy at the market ask price.
市场上的bid也就是买价是49.49
0.7%的bid ask spread可以用来计算市场的卖价：49.49*1.007= 49.84
为什么这里不是*（1-0.7%）呢？
