Stocks overcame early weakness to finish higher Monday, adding to last week’s positive action. The Nasdaq rose 0.3% after bouncing back from an 0.5% loss. Monday marked the tech-heavy index’s sixth straight gain — the longest winning streak since late November. But when it broke the streak, the Nasdaq went on a 5.5% pullback. The S&P 500 also rebounded from a 0.5% loss to rise 0.3%.