The Russell 3000 annual reconstitution takes effect June 30, and when it does, investors will see a slew of new companies, including 43 new healthcare and biotechnology companies.

At the same time, 40 other healthcare and biotech companies will fall out of the listing. In all, the index made 237 changes.

"Index reconstitution objectively captures the changing fortunes of companies and industries in the U.S. equity market," said Lori Richards, director of client services for the Tacoma-based company. "The important thing to note is that reconstitution provides investors with the current list of investment opportunities within all sectors to serve investors as reflective, unbiased tools," she said.

Indexes also have been used, increasingly, as the central focus of the quickly proliferating exchange-traded funds.

"It's an interesting twist this year that the same sector that sees the most movement in terms of the number of companies set for inclusion and removal," said Richards.

New companies represented in this year's reconstitution also include 39 consumer and discretionary service companies, 36 technology firms, and 34 financial services providers.

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