这里说的是如果交易从下单到真正被执行中时间的延迟增加，为什么说明市场有效性下降？谢谢

问题如下：

If the time lag between when an order to trade a security is placed and when the order is executed increases, how does the market efficiency changes correspondingly?

选项：

Market efficiency decreases.

Market efficiency stays the same.

Market efficiency increases.

解释：

A is correct.

If the time lag between when an order to trade a security is placed and when the order is executed increases, it is an indication that operating inefficiencies increases and it reduces market efficiency.

考点：Efficient Capital Market And Its Forms

题目问的是：一个交易指令，从下单到执行，这个之间的时间间隔延长了，说明什么？ 它说明市场的efficiency在下降。