The Dow Jones Wilshire 5000 Composite Index, also known as the Dow Jones Wilshire 5000 Total Market Index, is the most broadly based U.S. stock index. The index is comprised of four segments of market capitalization, each with a different index association.
1) Dow Jones Wilshire U.S. Large-Cap Index: Stocks ranked 1-750
2) Dow Jones Wilshire U.S. Mid-Cap Index: Stocks ranked 501-1,000
3) Dow Jones Wilshire U.S. Small-Cap Index: Stocks ranked 751-2,500
4) Dow Jones Wilshire U.S. Micro-Cap Index: Stocks ranked 2,501+
The mid-cap index contains stocks from both the small- and large-cap indexes. It contains approximately 250 of the smallest large-cap stocks and 250 of the largest small-cap stocks.