A pair of health-related companies in the Valley region announced they joined the Russell 3000 Index this week.

MannKind Corp. in Westlake Village, which sells inhalable insulin Afrezza, joined the index on Monday, following a “reconstitution” by FTSE Russell, the subsidiary of the London Stock Exchange Group that manages the Russell index portfolio. The indexes are used by investment managers and institutional investors as the basis for index funds and as benchmarks for investment strategies.

“As a constituent of the Russell 3000 Index, Mannkind will gain greater exposure to the investment community. We believe this will help generate more awareness around the progress we are making to increase shareholder value,” Chief Executive Michael Castagna said in a statement.

Apollo Medical Holdings Inc., a population health management company in Glendale, also joined the Russell 3000 Index and the Russell Microcap Index on Monday.

“We are honored to have been added to the Russell indexes, which we view as an acknowledgement of the significant progress we are making in building a physician-centric, integrated population health management company at the forefront of the U.S. movement towards value-based care," Dr. Warren Hosseinion, co-chief executive ApolloMed, said in a statement.