Below we highlight a few reasons that could boost S&P 500 ETFs ahead. Note that SPDR S&P 500 ETF Trust (SPY - Free Report) has gained about 17% over the past year and 14% so far this year. Fed rate cutsThe Fed signaled two additional rate reductions this year, which would take the benchmark down to 3.50-3.75% by December, as quoted on Yahoo Finance. In the 12 months after the start of an easing cycle, the S&P 500 has delivered an average return of 14.1%. This pattern should boost the S&P 500 over the medium term, if we go by the Northern Trust’s above-explained historical pattern.