NO.PZ2016031201000017
问题如下：
An arbitrageur will most likely execute a trade when:
选项：
A.transaction costs are low.
B.costs of short-selling are high.
C.prices are consistent with the law of one price.
解释：
A is correct.
Some arbitrage opportunities represent such small price discrepancies that they are only worth exploiting if the transaction costs are low. An arbitrage opportunity may require short-selling assets at costs that eliminate any profit potential. If the law of one price holds, there is no arbitrage opportunity.
中文解析：
A选项，交易成本很低有利于套利。选A。
B选项：做空的成本很高不利于套利，因为成本高可能使得套利无利可图。
C选项：价格始终遵守一价原则，即默认价格始终是合理的，那么就不会出现不合理定价从而产生套利机会。
老师，连续几道关于一价原则的题目，我都做错了。可能是英文理解的问题。错点是，存在一价原则，或者价格坚持一价原则，就没有套利空间。
那我想问，什么时候会选择一价原则呢？我经常理解，虽然一价原则是套利的结果，但是套利应该是基于一价原则才会发生的呀？
