Wilshire 5000 Index

The Wilshire 5000 Index is considered the "total market index." Designed to track the value of the entire stock market, the index was started in 1974 by Wilshire Associates soon after computers made the daily computation of such a large index possible.
The index includes a majority of the common stocks, REITs, and limited partnership shares, traded primarily through NASDAQ OMX or NYSE Euronext or the American Stock Exchange.

The Wilshire 5000 is comprised of virtually every stock that meets three criteria:
1) The firm's headquarters are based in the U.S.
2) The stock is actively traded on a U.S. exchange.
3) The stock has widely available pricing information (this disqualifies bulletin board, or over-the-counter stocks).
As of February 28, 2014 the index contained only 3,678 components. The index is intended to measure the performance of most publicly traded companies headquartered in the United States, with readily available price data, (Bulletin Board/penny stocks and stocks of extremely small companies are excluded). Hence, the index includes a majority of the common stocks and REITs traded primarily through New York Stock Exchange, NASDAQ, or the American Stock Exchange. Limited partnerships and ADRs are not included.

Wilshire 5000 index - $WLSH

It can be tracked by following the ticker $WLSH in http://stockcharts.com/h-sc/ui?s=$WLSH&p=D&b=5&g=0&id=p83998927006. It can be useful to track US stock market timing in addition to or in parallel to Mansfield RS (or the Relative Performance compared to an index such as the S&P 500).

The Wilshire 5000 Index is a very easy way to determine the path of the U.S. stock market. Since it includes essentially every public firm, it is highly representative of the overall market.

Because it is so diverse, it is impossible to tell which sectors or asset classes are moving the market (technology, industrial, small-cap, large-cap, etc) by merely looking at the Wilshire 5000. In addition, many people do not own a large number of the small-cap stocks that this index holds, so it may not accurately represent the portfolio mix held by most investors.