The Trade Desk stock down 80%-plus since mid-2025, S&P 500 removal imminent

Full analysis

The Trade Desk, the biggest independent way for advertisers to buy digital ads across the open web, has lost more than 80% of its stock value since mid-2025. Later this month it drops out of the S&P 500, the index of America's 500 largest public companies. Bankers at the ATS London conference held it up as proof that once a small-cap ad-tech story turns, it's brutally hard to turn back.

Here's the frame. This is a market event, not an operational one. The pipes still work. What's being decided is not whether The Trade Desk survives, but whether "scaled independent DSP as a standalone public company" is still a viable category, or whether the whole independent programmatic stack now reprices down together. Index removal is close to impossible to undo. Getting back into the S&P 500 requires rebuilding to a market-cap threshold that an 80% haircut put a long way off. The deadline is set by the mechanics: index funds must sell on the removal date regardless of what they think the company is worth.

The Market Analyst. Removal from the S&P 500 forces index funds to dump the stock on a fixed date, at any price, because their job is to match the index, not to judge the business. That's supply with no natural buyer underneath. The deeper problem is the comparison math. Screener models value Magnite, PubMatic, and Criteo partly off what The Trade Desk trades at, so a lower multiple on the leader drags the peers down mechanically. The investor base flips from growth funds to deep-value and distressed buyers, who ask different questions and hold for different reasons. For a generalist reader: the market just re-rated the whole independent ad-tech shelf, not one company.

The Skeptic. Slow down. This stock was trading at roughly 40 times revenue in early 2025. An 80% fall from that is a valuation coming back to earth, not a business falling apart. The Trade Desk still processes hundreds of billions of ad impressions. S&P 500 removal is a size trigger, and nothing about it says the product stopped working. For the bear case to be right, growth has to be permanently broken, not just soft for a couple of quarters, and connected TV, international, and identity are still real levers. The "cautionary tale" line at a banking conference is theater. For a generalist: the chart looks like a catastrophe mostly because you're measuring from the peak.

The Strategist. The fall is the clearest evidence yet that the independent DSP was never as protected as the 2020 bull case claimed. Walled gardens like Google, Meta, and Amazon keep compounding their advantage in logged-in user data. Retail media networks push dollars into closed systems. And AI-driven buying tools from Amazon and Google chip away at the value of The Trade Desk's identity layer, its system for tracking users without cookies. The two-year read is consolidation pressure across the whole independent stack. For a generalist: the "champion of the open web" story sold better as a story than it held up as a durable business advantage.

The Operator. Forget the stock for a second, then remember it, because your clients won't forget it. When a brand's or agency's finance team sees an 80% drop and an index removal, they start asking whether this vendor can still fund its roadmap and honor its support commitments. Renewal talks get harder. Procurement starts writing in fallback language naming a second DSP. And the account teams at Google's DV360 and Amazon DSP are already in those meetings, pointing at the chart. The operational capability hasn't changed. The perceived risk of depending on it has.

The CFO. The real cost here isn't the share price, it's the second-order drag. A depressed stock makes it harder to retain engineers paid partly in equity, and talent walking out the door is how a "the pipes still work" story quietly becomes a "the pipes are aging" story. The flip side is opportunity. A strategic buyer, a Publicis or a large holding company, can now look at The Trade Desk's customer relationships and engineering bench at a fraction of the 2024 price. Whether that math tempts anyone depends on how cheap is cheap enough.

Where the council splits. Three real disagreements.

First, correction or collapse. The Skeptic sees an overpriced stock returning to a sane number. The Strategist sees the market waking up to a structural weakness that was always there. Same 80%, opposite meanings.

Second, contained or contagious. If this is just The Trade Desk digesting a crazy valuation, the peers are fine. If the screener math and the walled-garden story are the drivers, then Magnite, PubMatic, and Criteo reprice whether their own numbers justify it or not.

Third, overhang or reset. The Market Analyst flags loss aversion: holders anchored to the old highs refuse to sell, so the stock bleeds slowly instead of resetting clean. That prolonged bleed is exactly what feeds the procurement fear the Operator described.

What it hinges on. Two beliefs. One, is the growth slowdown cyclical or structural. Two, does a lower multiple on the leader mechanically drag the independent peers regardless of their own results. The council leans structural on the second point even while staying agnostic on the first. The re-rating of the category is already happening in the comparison models. What's worth checking before acting on any of it: The Trade Desk's next two revenue prints for whether connected TV and international growth actually reaccelerate, and the peers' multiples for whether they compressed in step with The Trade Desk regardless of their own numbers.

Prediction: At least one of Magnite, PubMatic, or Criteo will announce a take-private deal, a strategic acquisition, or a formal strategic-review/sale process by the close of Q1 2027 earnings season (roughly end of February 2027).

Confidence: Medium — the category re-rating is real, but M&A timing depends on a willing buyer.

Why: The Trade Desk's index removal forces index funds to sell mechanically and re-anchors the comparison math that screener models use to value Magnite, PubMatic, and Criteo, so all three reprice down whether or not their own results deteriorated. A depressed public multiple across the independent stack is exactly the condition that makes a company cheaper to buy whole than to keep funding as a standalone public entity, and holding companies and strategic buyers have motive to grab customer relationships and engineering talent at these prices. The opposite outcome, everyone staying independent and public, is the less likely one because the whole point of the ATS London warning is that a broken small-cap narrative doesn't reverse on its own, which pushes boards toward a sale rather than a slow bleed.

Revisit by 2027-03-01: We're right if any of Magnite, PubMatic, or Criteo announces a take-private, a strategic acquisition, or a publicly disclosed sale/strategic-review process by the end of February 2027 earnings season. We're wrong if all three remain independent public companies with no announced deal or formal review process by that date.