
Chinese: 
Jules Regnault 于 1863 年最早提出了有效市场理论
这个理论最终演变成了有效市场假说
Eugene Fama 在上世纪 60 年代继续完善这些理论
并在他的博士论文中阐述了这个概念
Fama 最近荣获了诺贝尔奖 所以这些理论肯定很有用
什么是有效市场假说？
先来看看它做出的一些假设
最重要的假设可能就是
市场上有很多投资者都希望获得收益
所以他们渴望找到
股价与真实价值不一致的机会
因为有很多投资者同时在操作
所以任何时候只要出现一点信息 价格就会变动
下一条假设是新信息随机出现

English: 
The first ideas that eventually became
the Efficient Markets Hypothesis
were postulated by
Jules Regnault in 1863.
Eugene Fama carried those
ideas further in the 1960's,
and it became his PhD thesis.
Fama recently received a Nobel Prize,
so we know those ideas were good.
So what's the efficient
market hypothesis about?
We'll start by looking at some of
the assumptions that it makes.
Probably the most important assumption
is it that there are a large
numbers of investors interacting
in the market for profit.
So they have an incentive
to find opportunities
where the price of a stock is out of
line with what its true value is.
Because there are so many of these
investors operating simultaneously, any
time a little bit of information comes
out there, the price is going to move.
The next assumption is that new
information arrives randomly.

English: 
So it arrives at random times,
it arrives at random rates for
different stocks, but
it's constantly arriving and
investors are paying attention
to that information and
therefore the prices
are adjusting quickly.
Finally, the efficient
market hypothesis assumes
that the current price reflects
all available information.
In other words, all this information
that's trickling in is acted upon by
the investors, the price adjusts
quickly to that information, and
the current price reflects all of
the information about that stock.

Chinese: 
即新信息在随机时间以随机速率出现
并且针对不同的股票 但是会不断出现
投资者一直在关注这些信息
所以价格会快速调整
最后 有效市场假说
假设当前价格体现了所有可用的信息
即 投资者会根据出现的所有信息采取行动
价格根据这些信息快速调整
当前价格体现了关于某个股票的所有信息
