IWR tracks the Russell Midcap index, competing with Vanguard's VO. Its top holdings include names like Snowflake and Marathon Petroleum, giving it a somewhat different composition from VO.

Its 16.1% one-year return has edged out VO's 13.7%, but at a 0.18% expense ratio — much higher than VO's 0.03%. For long-term holding, VO is often the more cost-efficient choice.