Stock Market Today, March 5: The Trade Desk Soars on Reports of OpenAI Ad Sales Talks and Insider Buying

2026-03-05 17:51:55 ET

The Trade Desk (NASDAQ:TTD) , a digital ad-buying platform provider, closed Thursday at $29.79, up 18.36%. The stock rallied after reports of exploratory OpenAI ad-sales talks and a large CEO share purchase hit the newswire. Investors are watching whether any formal partnership emerges to monetize AI-driven ad inventory . Trading volume reached 82.2 million shares, about 405% above its three-month average of 16.3 million shares. The Trade Desk IPO'd in 2016 and has grown 890% since going public.

The S&P 500 slipped 0.58% to 6,830, while the Nasdaq Composite eased 0.26% to 22,749 as growth names lost some momentum. Within advertising agencies, industry peers PubMatic closed at $8.87, up 1.60%, and Magnite finished at $14.16, gaining 2.39%, lagging The Trade Desk’s sharp move.

The Trade Desk rallied today over two key pieces of news. First, the company announced that it was in “early discussions” with OpenAI to help the AI behemoth rollout advertising on its platform. While I’m partially optimistic, as this deal highlights the value of TTD’s offerings, rather than OpenAI building its own, the company is also cozying up to one of the “Walled Gardens” it typically differentiates itself from.

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