The Trade Desk remains one of the highest-quality companies in ad tech, but a great business is not automatically a great investment.The Trade Desk (TTD 1.00%) enters 2026 as one of the most debated stocks in digital advertising.The company remains a high-quality operator with strong long-term positioning. Yet the competitive landscape, once favorable, now looks more crowded than ever. As a result, investors face an increasingly nuanced question: Is The Trade Desk still a buy going into 2026?The honest answ ...