Russell reconstitution adds to U.S. market's volume, volatility

Traders work on the floor of the New York Stock Exchange (NYSE) in New York, U.S., June 24, 2016. REUTERS/Lucas Jackson

NEW YORK (Reuters) - FTSE Russell reconfigured its indexes at the close in an annual event that triggered the highest trading volume for any session in almost five years and added to Friday’s high volatility in the U.S. stock market.

Trades in about 933 million shares representing $20.6 billion were executed in Nasdaq’s “closing cross” in 0.8 seconds across some 2,464 Nasdaq-listed stocks, according to bourse.

The closing cross brings together the buy and sell interest in specific Nasdaq, NYSE and NYSE MKT stocks and executes all shares for each stock at a single price, Nasdaq said. The closing prices determined by the closing cross are widely used throughout the industry.

Volume on U.S. exchanges Friday totaled 15.3 billion, the highest since August 2011, according to Bats Global Markets, with Britain’s vote to leave the European Union also rattling investors.

On the Russell reconstitution day in June 2015, U.S. equity volume was just 10.1 billion, Bats data showed.

Newly reconstituted index membership will take effect when markets open on Monday.

A final list of the changes also is due to be released on Monday, but Wall Street analysts said preliminary lists of the changes showed that in the Russell 2000 small company index, financial firms and consumer staples companies lose weighting and materials companies and producer durables have a stronger role.

In the Russell 1000 large capitalization company index, Apple Inc AAPL.O was to lose its weighting and also be classified as both a value and a growth company at Russell.

Reporting by Caroline Valetkevitch; Editing by Alan Crosby