Generated October 17, 2026.
Overview
IJR and IWM are both broad small-cap stock ETFs launched on the same day, but they track different indexes. IJR follows the S&P SmallCap 600, which focuses on companies in the 600–2,500 market-cap range, while IWM tracks the Russell 2000, a broader measure of roughly 2,000 small-cap stocks. The key distinction is the index methodology: S&P uses market-cap weighting with a capped constituent weight, whereas Russell 2000 uses pure market-cap weighting and reconstitutes annually, which can drive different holdings and performance.
How they differ
IJR's underlying S&P SmallCap 600 excludes the smallest stocks in IWM's Russell 2000, meaning IJR's portfolio skews toward the larger end of small-cap. IWM's beta of 1.27 versus IJR's 1.07 reflects this: Russell 2000 stocks are more volatile. On cost, IJR is cheaper at 0.06% compared to IWM's 0.19%—a 0.13% difference that compounds over decades. IJR yields slightly more at 1.50% versus 1.11%, though both pay dividends quarterly. IJR also holds a larger asset base at $103B versus $78.7B.
Who each is best for
IJR: Fits investors seeking lower-cost exposure to the larger small-cap segment, with a modest yield and reduced volatility relative to the broader small-cap universe. This can trigger predictable trading flows and temporary liquidity imbalances as investors adjust holdings around the reconstitution date, potentially affecting execution quality.
- Beta and drawdown magnitude. IWM's 1.27 beta indicates roughly 27% greater price swing magnitude than the broader market during market stress; IJR's 1.07 beta is lower but still amplified relative to the S&P 500, meaning both funds will decline sharply in recession or equity downturns.
- Concentration and sector overlap. Both funds' exposures may overlap significantly (holdings data not provided here), and small-cap indexes often concentrate in specific sectors. A downturn in financials or industrials, common small-cap heavyweights, could pressure both simultaneously.
- Liquidity in the smallest constituents. IWM's inclusion of the 2,000th-largest stock introduces exposure to less-liquid names; during market stress or forced selling, bid-ask spreads on those holdings can widen, potentially increasing realized trading costs for the fund.
Bottom line
If you want the lower fee and slightly higher income from the better-capitalized small-cap segment, IJR's $103B asset base and 0.06% ratio are attractive. If you prefer the Russell 2000's broader definition and accept its 1.27 volatility and 0.19% fee, IWM offers exposure further down the market-cap scale. Both have tracked their indexes faithfully over decades; past performance does not predict future results.
AI-generated analysis for educational purposes only. Verify important details independently; past performance does not guarantee future results.