This growing adtech company deserves its premium valuation.The Trade Desk (TTD -0.24%) has generated impressive gains since its initial public offering in September 2016. The adtech company went public at a split-adjusted price of $1.80, reached a record high of$111.64 on Nov. 16, 2021, and eventually pulled back to about $92 today. That rally would still have turned a$20,000 investment into $1.02 million.Investors might be reluctant to buy the stock after those massive gains, and it doesn't look cheap at ...