The US stock market has traded mostly sideways this year—the S&P 500 Index of stocks is up a meager 0.44% on a total-return basis.
But it could be worse. Amazon’s 34.5% rally boosted the broader index of stocks by 0.65%, putting it in positive territory, according to Howard Silverblatt, senior index analyst at S&P Dow Jones Indices. Without the e-commerce giant’s buoyant gains, the S&P gauge would be down 0.21% this year.