Caterpillar Inc. shares reversed early gains Tuesday to trade sharply lower, after executives on the company's earnings call said the first quarter was likely the "high watermark" for the year. "While we expect strong operating margins for the rest of the year, which is defined as within or better than the Investor Day ranges, we do not expect to repeat first quarter operating margin at the consolidated level," Chief Financial Officer Bradley Halverson told analysts on the call. The construction equipment maker's shares were last down 6%, the worst decline since June of 2016. Earlier, the stock had gained about 4.6% at its peak. Caterpillar shares are up 49% in the last 12 months, while the Dow Jones Industrial Average has gained 15% and the S&P 500 has gained 11%.