干 找了好几个段落想说有没有比较好打的 靠邀 看起来都一样难打
烦死了 为什么连PTT系统英文字也比较吃香 到底是?????
考研究所为什么要唸这烂东西
Market indexes
If we found our attention on U.S. stocks, then rather than construct the
market porfolio ourselves, we can make use of several popular market indexes
that try to represent the performance of the U.S. stock market.
Examples of Market indexes.
Amarket indexes reports the value of a particular porfolio of securities.
The S&P 500 is an index that represents a value-weighted of 500 of the largest
U.S. stocks. The S%P 500 was the first widely publicized value-weighted
portfolio of 500 of the largest U.S. stocks. The S&P 500 usd to represent
"the market portfolio" when usingthe CAPM in practice. Even though the S&P
500 includes only 500 of the roughly 5000 publicly traded stocks in the U.S.
,because the S&P500 includes the largest stocks, it represents almost 80% of
the U.S. stock market in terms of market captaliztion.
More recently created indexes, such as the Wilshire 5000, provide a
value-weighte index of all US stock listed on the major stock exchanges. While
more complete than S&P 500 and therefore more representative of the overall
market, its returns are very similar; between 1990 and 2017, the correlation
between their weekly returns are very nearly 99%. Given this similarity, many
investors view the S&P 500 as an adequate meaasure of overal U.S. stock market
performance.
The most widely qouted U.S. stock index is Doq Jones Industrial Average (DJIA),
which consists of a portfolio of 30 large industrial stocks. While somewhat
representative, the DJIA clearly does not represent the entire market. Also,
the DJIA is a price-weighted(rather than value-weighted portfolio.)A
price-weighted holds an equal number of shares of its stock, independent of
their sized. Despite being nonrepresentaive of the entire market, the DJIA
remains widely cited because it is one of the oldest stock market indexes
(first published in 1884).