Market reaction
Shares of Opus Genetics Inc (IRD) climbed 6.5% on Friday after an announcement that the clinical-stage biopharmaceutical firm will be included in three Russell indexes. The move to add the company to the Russell 3000, the Russell 2000 and the Russell Microcap indexes takes effect when U.S. markets open on June 29, 2026.
Index addition details
The inclusion comes as part of the June 2026 Russell indexes reconstitution. That periodic process reviews the universe of U.S. stocks and captures up to the 4,000 largest companies as of April 30, ranking them by total market capitalization. Being placed in the Russell 3000 Index also results in automatic membership in either the large-cap Russell 1000 Index or the small-cap Russell 2000 Index, along with the corresponding growth and value style indexes.
How membership is determined
FTSE Russell determines index membership primarily using objective market-capitalization rankings and style attributes. The company’s methodology emphasizes measurable criteria rather than discretionary selection. Russell indexes are commonly used by investment managers and institutions both as the basis for index funds and as benchmarks for active strategies.
Scale and market context
FTSE Russell reports that, as of the end of June 2025, about $12.2 trillion in assets were benchmarked to the Russell U.S. indexes. That broad adoption helps explain why additions and removals from these indexes can attract investor attention and trading activity when changes are announced.
Company focus
Opus Genetics is a clinical-stage biopharmaceutical company developing gene therapies for inherited retinal diseases. The company’s addition to multiple Russell indexes marks a notable event for its public equity, coinciding with the formal reconstitution timeline and the April 30 market-cap ranking cutoff used by FTSE Russell.
Note: The inclusion is scheduled to take effect at the opening of U.S. markets on June 29, 2026, per the June 2026 Russell reconstitution schedule.