What happened
Shares of The Trade Desk (TTD 0.66%) rose 208.3% last year, according to data from S&P Global Market Intelligence. The company, which operates a platform connecting digital media outlets with advertisers, benefited from explosive consumer interest in connected TV devices and services, where The Trade Desk is a leading seller of ad space.
So what
The path to massive growth wasn't clear in the early going. The Trade Desk's revenue sputtered in August's second-quarter report, falling 13% year over year to trigger a 10% sell-off in the span of three market days. But the surging media market soon made it obvious that The Trade Desk has found a valuable ad-selling niche, and share prices started to climb again in September.
November's third-quarter report put the whole debate to rest with positive surprises across the board, including revenue 20% above Wall Street's consensus estimates and triple the expected earnings. The Trade Desk closed 26% higher the next day.
Now what
The smooth sailing ended on Dec. 28. The shares fell 10.6% that day as investors in many high-flying growth stocks decided to cash in some of their profits right before the end of the tax year. The stock has continued to fall from there, stepping down by a couple of percentage points four times over the last two weeks.
That's just an ordinary bout of growth-stock volatility and year-end market mechanics and nothing to panic over. The Trade Desk's business hasn't changed even though the stock now trades nearly 22% below December's all-time highs. That's a buying opportunity in my eyes.