Instead of making a bee-line to the SPDR S&P 500 ETF (NYSEArca: SPY) as the default exchange traded fund for S&P 500 index exposure, investors can also consider an outperforming equal-weight approach.

The Guggenheim S&P 500 Equal-Weight ETF (NYSEArca: RSP) has gained an average annualized 9.6% over the past ten years, compared to the 7.4% return for SPY. Year-to-date, RSP is up 24.6% while SPY increased 20.8%.

The equal-weight methodology provides investors with performance potential, diversification and a disciplined rebalancing schedule, Bill Belden, Managing Director and Head of Product Development at Guggenheim Investments, said in a note.

The equal-weight methodology is outperforming its market-cap-weighted ETF rivals this year thanks to the outperformance of smaller stocks, and mid-caps in particular. [Equal-Weight ETF Still Beating the S&P 500 a Decade Later]

“Since inception, Guggenheim S&P 500 Equal Weight has outpaced the market-weighted S&P 500. Equal-weighting’s primary advantage compared with market-cap weighting comes from its greater exposure to higher-risk but higher-return small-cap stocks,” says Morningstar analyst Michael Rawson in a report on RSP.

By equally weighting component holdings, RSP diminishes concentration risk and provides a more balanced exposure across sectors.