NO.PZ2015122802000026
问题如下：
Consider the following limit order book for a stock. The bid and ask sizes are number of shares in hundreds.
A new buy limit order is placed for 300 shares at ¥123.40. This limit order is said to:
选项：
A.take the market.
B.make the market.
C.make a new market.
解释：
C is correct.
This order is said to make a new market. The new buy order is at ¥123.40, which is better than the current best bid of ¥123.35. Therefore, the buy order is making a new market. Had the new order been at ¥123.35, it would be said to make the market. Because the new buy limit order is at a price less than the best offer of ¥123.80, it will not immediately execute and is not taking the market.
考点：Execution Instructions
题目列出了当前市场上dealer的买卖报价，现在市场中出现一个新的买价以123.4买300股。问该买单可以被看作是：
A. 报价可以成交。take the market就是以报出的指令价格成交。打比比方buy order价格正好等于best ask，立即成交了，这就是take the market。但是现在报价123.4低于dealer最低的卖价123.8，因此该订单没法成交。
B.可以看作是一次做市。make the market指如若买价报在best bid或卖价报在 best ask,就是一次做市。本题的best bid和 best ask分别为123.35和123.8，而新报的买价是123.4没有落在123.35，所以这不叫make the market。
C.可以看作是做了一个新市。make a new market, 它是指报价报在最高的bid和最低ask之间就叫做make a new market。根据dealer的买卖报价，make a new market的范围是（123.35-123.8）也就是best bid-best ask，而123.4正好落在这个区间，所以是make a new market.
ask报在123.8以上还是必须等于123.8才叫做make a market？
