The S&P 500 has risen about 10% this year and is hovering near its all-time highs. That rally was largely driven by the tech sector's robust growth rates, big buybacks, earnings beats across the market, easing trade tensions, and hopes for deeper interest rate cuts. But with a price-to-earnings ratio of 30, the S&P 500 also looks historically expensive. However, some of the S&P 500's top stocks are outperforming the benchmark index by a wide margin but still trading at reasonable valuations.