The Russell Top 200 Index measures the performance of the 200 largest companies in the Russell 1000 Index, with a weighted average market capitalization of $186 billion. The median capitalization is $48 billion; the smallest company in the index has an approximate capitalization of $14 billion.
The index was launched on September 1, 1992 by Russell Investments and is maintained by FTSE Russell, a subsidiary of the London Stock Exchange Group. Its ticker symbol is ^RT200.Wikipedia