Generated June 2026 from current fund data.
Overview
SPLG and SPY are both State Street S&P 500 tracking ETFs that hold identical underlying exposure—the 500 largest U.S. companies. The critical difference is cost: SPLG charges 0.02% annually while SPY charges 0.10%, making SPLG eight times cheaper. SPY is the original and far larger fund with $783B in assets; SPLG launched 12 years later as a lower-cost alternative within State Street's portfolio lineup.
How they differ
The expense ratio gap is the defining distinction. SPLG's 0.02% fee versus SPY's 0.10% means that over 20 years, the difference in cumulative costs compounds to roughly 0.4 percentage points of total return—a material drag on a fund held for decades. SPY has a significant size advantage at $783B in assets, which translates to tighter bid-ask spreads and higher daily trading volume, useful if you're moving large positions or need instant liquidity. Both funds have identical beta (1.0) and distributions, and both track the same index, so the performance difference over time will almost entirely reflect that 0.08% annual fee gap.
Who each is best for
SPLG: Fits investors building a core S&P 500 holding in a buy-and-hold portfolio where cumulative fee savings matter over a multi-decade horizon, and who are comfortable with smaller trading volume.
SPY: Fits investors who prioritize maximum trading liquidity and the smallest possible bid-ask spread, or who plan to trade the position actively rather than hold it for decades; also fits those who value the option to use options strategies tied to the most heavily traded S&P 500 vehicle.
Key risks to know
- Fee erosion at identical returns. Both funds track the same index, so any outperformance by SPY relative to SPLG will be due to lower tracking error—yet SPY's higher expense ratio works in the opposite direction. Over 15+ years, the fee drag is the dominant factor in relative returns.
- Concentration in the largest 500 names. Both funds have heavy weighting to the "Magnificent Seven" mega-cap tech stocks and other concentration at the portfolio level; a sharp downturn in large-cap U.S. equities affects both identically. This is not diversification into small-cap or international equity.
- Liquidity mismatch for smaller investors. While SPY's $783B AUM ensures tight spreads during normal trading, SPLG's smaller size means less depth; selling a very large SPLG position during a market dislocation could face wider spreads than SPY, eroding returns in that scenario.
Bottom line
If you hold either fund for a long buy-and-hold horizon, SPLG's lower fee will compound into meaningfully better returns; if you trade frequently or need guaranteed tight spreads during stress, SPY's liquidity and options ecosystem justify the higher cost. Neither fund offers yield—SPY's 1.04% distribution rate is minimal and typical of equity index funds—and both are pure vehicles for U.S. large-cap equity beta, not income generation. Past performance doesn't predict future results.
AI-generated analysis for educational purposes only. Verify important details independently; past performance does not guarantee future results.