The Wilshire 4500 Completion Index, more commonly the Wilshire 4500, is a market capitalization

Market capitalization

Market capitalization is a measurement of the value of the ownership interest that shareholders hold in a business enterprise. It is equal to the share price times the number of shares outstanding of a publicly traded company...

-weighted index

Stock market index

A stock market index is a method of measuring a section of the stock market. Many indices are cited by news or financial services firms and are used as benchmarks, to measure the performance of portfolios such as mutual funds....

 of all stocks

Common stock

Common stock is a form of corporate equity ownership, a type of security. It is called "common" to distinguish it from preferred stock. In the event of bankruptcy, common stock investors receive their funds after preferred stock holders, bondholders, creditors, etc...

 actively traded in the United States with the exception of the stocks included in the S&P 500

S&P 500

The S&P 500 is a free-float capitalization-weighted index published since 1957 of the prices of 500 large-cap common stocks actively traded in the United States. The stocks included in the S&P 500 are those of large publicly held companies that trade on either of the two largest American stock...

 index. The index is created by removing the stocks in the S&P 500

S&P 500

The S&P 500 is a free-float capitalization-weighted index published since 1957 of the prices of 500 large-cap common stocks actively traded in the United States. The stocks included in the S&P 500 are those of large publicly held companies that trade on either of the two largest American stock...

 Index from the Wilshire 5000

Wilshire 5000

The Wilshire 5000 Total Market Index, or more simply the Wilshire 5000, is a market-capitalization-weighted index of the market value of all stocks actively traded in the United States. Currently, the index contains over 4,100 components...

.

Many managers of small-cap and mid-cap funds use the Wilshire 4500 as a performance benchmark. For example, Thrift Savings Plan

Thrift Savings Plan

The Thrift Savings Plan is a defined contribution plan for United States civil service employees and retirees as well as for members of the uniformed services....

's small-cap fund tracks the float-adjusted total return

Wilshire 5000

The Wilshire 5000 Total Market Index, or more simply the Wilshire 5000, is a market-capitalization-weighted index of the market value of all stocks actively traded in the United States. Currently, the index contains over 4,100 components...

version of this index.