The term MSCI U.S. Mid Cap 450 Index refers to a composite that includes mid cap companies located in the United States. The MSCI U.S. Large Cap 450 is published and maintained by Morgan Stanley Capital International (MSCI).
The MSCI U.S. Mid Cap 450 is designed to measure the performance of the mid-capitalization companies in the United States. The index represents roughly 15% of the free float adjusted market capitalization of the U.S. equities market. At the time of writing, there were 441 constituents in the index.
First launched on March 27, 2003, the MSCI U.S. Mid Cap 450 is designed to provide investors with a measure of the performance of the mid-cap U.S. equity market. Companies are selected based on float-adjusted market capitalization. All MSCI market capitalization indexes are fully reviewed at the end of May and November. Partial reviews take place in February and August. The performance of this index can be monitored via Bloomberg's real time ticker symbol MZUSM.