CTV and Channel Mix

Where the growth is coming from

The deceleration is not spread evenly across the platform. In the March 2026 quarter, video — which includes connected TV — grew about 21% year over year on the company's own channel disclosures, while everything else grew about 3% and mobile, roughly 29% of the platform, shrank. Video is still compounding. The mix shift it produces, though, adds well under a point a year to total growth.

Nineteen quarters of channel mix

The Trade Desk publishes no channel split in its 10-K. It describes one in words on almost every earnings call — "a mid-40s percentage share", "a high-28s percent share" — and has done so consistently enough that the phrasing can be assembled into a series no filing contains.

In the June 2021 quarter, mobile was the largest channel at a low-40s percentage share and video, including CTV, was a high-30s share [1]. The two were level at about 40% each by the September 2021 quarter [2] and again in the March 2022 quarter [3]. By the March 2026 quarter, video was a low-50s percent of the business and mobile a high-28s percent [4].

Midpoints of the verbal bands given in the quarterly prepared remarks; the December 2021 quarter gave no numeric share for either channel and is omitted. Sources: Q2 FY2021 [5]; Q3 FY2021 [6]; Q1 FY2022 [7]; Q2 FY2022 [8]; Q3 FY2022 [9]; Q4 FY2022 [10]; Q1 FY2023 [11]; Q2 FY2023 [12]; Q3 FY2023 [13]; Q4 FY2023 [14]; Q1 FY2024 [15]; Q2 FY2024 [16]; Q3 FY2024 [17]; Q4 FY2024 [18]; Q1 FY2025 [19]; Q2 FY2025 [20]; Q3 FY2025 [21]; Q4 FY2025 [22]; Q1 FY2026 [23].

At the midpoints, the four named buckets — video, mobile, display and audio — account for about 99% of the platform in the March 2026 quarter, so they are being reported as mutually exclusive, leaving little room for digital-out-of-home and native [24]. The boundary between two of them is not defined anywhere in the filings: the same remarks that separate mobile from video have also described growth inside mobile as "solid across in-app and mobile video" [25].

What the shares imply about growth

Revenue in the March 2026 quarter was $688.9 million against $616.0 million, up 12% [26]. Applying the band midpoints to that base — video at 48% a year ago and 52% now, mobile at 35% and 28.7%, audio at 5% and 6% — gives the implied growth of each channel.

Derived: quarterly revenue from the Q1 FY2026 Form 10-Q [27], channel shares from the Q1 FY2025 [28] and Q1 FY2026 [29] prepared remarks, midpoints applied.

The decomposition reconciles: 48% of the prior-year base growing 21.1% plus 52% growing 3.2% produces 11.8%, the reported figure [30]. Taking the widest reading of both bands, video grew between 16% and 26%, mobile fell between 5% and 12%, and the non-video half of the platform lies between a 1% decline and 7% growth. The audio figure has an independent check: management said audio "grew year over year at a rate higher than any other channel in Q1", which is what a move from around 5% to around 6% of a business growing 12% implies [31].

The same exercise on the volume metric over the full year is directionally identical but less precise. Gross spend rose 11% to $13.39 billion in FY2025 from $12.04 billion [32]. Averaging the four quarterly midpoints puts video at 47.25% of spend in 2024 and 49.0% in 2025, which implies video gross spend of roughly $5.69 billion rising to $6.56 billion, up 15%, against 8% for everything else. Because the annual share moved less than two points, the band corners are wide enough that the two rates could be as close as 11% and 12%; the quarterly comparison, where the share moved four points and one bucket was quoted to a tenth, is the tighter test.

How the channel language changed

For three years the description of CTV was a superlative, repeated almost verbatim. It was "our fastest growing channel and it has rapidly become our largest" for the September 2022 quarter [33]; CTV "by a wide margin, led our growth again during the quarter" for the June 2024 quarter [34]; "our largest and fastest growing advertising channel" for the March 2025 quarter [35].

The wording then loosened, though not in a straight line. In the September 2025 quarter the two framings sat side by side: the CEO still called CTV the company's "largest and fastest-growing channel" [36], while the CFO's version of the same claim was relative rather than absolute — CTV "has been consistently growing at a faster rate than the overall business" [37]. For the December 2025 quarter the superlative itself was downgraded to "one of our fastest-growing channels", with audio named as the channel that grew faster than any other in the quarter [38] [39]. In the March 2026 quarter no superlative was attached to CTV at all: growth was "driven by strong trends across CTV and audio", and audio again grew faster than any other channel [40].

That sequence tracks the arithmetic rather than contradicting it. Video decelerating from a rate in the thirties to roughly 20% while the total decelerates to 12% is exactly the pattern that turns a superlative into a comparative. What the company has never disclosed, in any filing or on any call in the archive, is a consolidated CTV growth rate or a CTV dollar figure; the closest it has come is regional colour, as when CTV across EMEA and North Asia was described as "growing over 100% year-over-year in each region" in the September 2023 quarter [41]. The last platform-wide CTV operating metric was in August 2021: "nearly 10,000 CTV advertisers on our platform, up over 50% compared to last year" [42].

Sizing the tailwind

The FY2025 10-K opens its industry section with digital advertising at over $700 billion of annual spend and more than 70% of the total advertising market, a global advertising TAM reported past $1 trillion for the first time in 2024, and "Rapid Growth of CTV" as the first of six trends listed [43]. The promotion is new: the FY2024 filing led with media becoming increasingly digital and placed the emergence of CTV third [44].

Neither the company nor its filings size CTV itself. A competitor's does. Viant Technology, an independent demand-side platform that runs the same buy-side model and owns no inventory, quotes third-party forecasts in its own FY2025 10-K: US CTV advertising reaching $38.0 billion in 2026, continuing at double-digit annual growth rates, surpassing traditional TV advertising in 2029 at $52.5 billion; 89% of US CTV ad spend already transacted programmatically in 2025, rising to 93% by 2027; US programmatic advertising growing at a 12% compound rate from 2024 to 2027 to $225.3 billion, taking programmatic from 40% to 46% of total US media spend [45].

Third-party forecasts quoted in Viant Technology's FY2025 Form 10-K [46].

Two things follow. The first is that headroom is not the binding constraint: The Trade Desk bought roughly $6.6 billion of video inventory globally in FY2025 on the midpoint shares, against a US CTV market forecast at $38.0 billion for 2026 alone. The second is that video growing 15% to 21% against a market forecast to grow at a low-double-digit rate means the company is, at worst, holding its position in the channel the bull case is built on — the deceleration is happening somewhere else on the platform.

Three facts cut against reading that as a durable tailwind. With 89% of CTV spend already transacted programmatically, the conversion leg of the CTV story is close to finished inside the channel; what remains has to come from linear budgets migrating and from price, which is slower and more mechanical than a penetration curve [47]. YouTube, the largest single streaming advertising property, grew ad revenue 11.7% in 2025, to $40.4 billion from $36.1 billion — a global figure against a US market forecast, but a reminder that the shift to streaming was not delivering 20% growth to the biggest incumbent either [48]. And the supply side is not passive: Viant markets a programme built on "the removal of resellers from the digital supply chain" through direct partnerships with CTV publishers [49], while The Trade Desk's own risk factors note that "a few inventory suppliers hold a significant portion of the programmatic inventory" [50].

What the mix can and cannot do

Total growth is the weighted sum of two very different businesses. At the March 2026 base — video 52% of the platform, everything else 48% — the arithmetic is fully determined by the two growth rates.

Derived: total growth equals 0.52 times video growth plus 0.48 times growth in all other channels, using the March 2026 channel mix [51].

Consensus of roughly 9.7% revenue growth in FY2026 and 9.6% in FY2027 (Financials and Estimates) sits close to the cell where video compounds near 20% and the rest of the platform is flat to slightly down — that is, the street is underwriting the pattern the March quarter already showed rather than a repair of it.

The mix shift does work in the company's favour, but slowly. Holding video at 20% growth and the rest of the platform exactly flat, total growth rises from 10.4% in the first year to 11.3%, then 12.2%, then 13.0% in the fourth, as video's share climbs from 52% to about 69%. That is roughly 80 to 90 basis points of total growth a year purchased by arithmetic alone. A return to the high-teens rates of 2023 and 2024 needs something more than mix: either CTV re-accelerating well above 20%, or the 48% of the platform that is currently flat to shrinking finding a floor.

Limits of the disclosure

The shares are verbal bands offered on calls, not audited figures, and the midpoint convention can be off by a point in either direction per bucket — which is why the growth estimates above are given as ranges rather than points. The video bucket blends CTV with non-CTV online video, so a CTV-only growth rate is not observable from anything the company publishes; the risk factors state only that "the demand for CTV inventory on our platform has been a significant driver of growth" [52]. The shares are described as shares of spend, while the quarterly base they are applied to is revenue; differing take rates by channel would move the implied levels, though not the direction of the gap. The borrowed forecasts have a problem of their own: the segment breakdown further down the same page of that competitor filing puts US CTV advertising at $38.0 billion in 2026 growing to $42 billion by 2028, a 12% compound rate, which does not reconcile with the $52.5 billion for 2029 stated a few paragraphs earlier [53]. Either path still leaves the channel several times larger than the video volume the company currently buys. And the run's web-research access was unavailable, so no independent estimate of The Trade Desk's CTV share could be checked against any of these figures.

One initiative aimed squarely at CTV supply is worth marking for its disclosure status rather than its economics. The Ventura operating system for connected television was announced on the February 2025 call [54]; fifteen months later the CEO described "great partnership discussions with our operating system for CTV called Ventura" and said more would be heard "in the years to come" [55]. It is not named anywhere in the FY2025 10-K, which does name OpenPath, OpenAds, OpenSincera and PubDesk among the products built to improve supply-chain quality [56]. On the record available, Ventura carries no revenue, no partner count and no timetable.

The read

The evidence points to a company whose CTV franchise is intact and whose problem sits in the other half of the platform. Video grew about twice as fast as everything else across FY2025 on gross spend and roughly six times as fast in the March 2026 quarter, it is growing at or above the rate forecast for the programmatic market, and its share of spend has climbed from a high-30s to a low-50s percentage across the nineteen disclosed quarters without one reported decline. Against that, mobile — the second-largest channel — is now shrinking in absolute terms, and mix arithmetic alone buys back under a point of total growth a year.

The strongest fact against this reading is that it rests on management's own verbal bands, unaudited and unaccompanied by any CTV-specific figure, in a period when the company retired the superlative it had used for CTV on more than a dozen calls. Two observations would change it. If the video share stops rising while total growth stays in single digits, video growth has converged with the rest of the platform. If mobile's decline stops and display holds, the same 20% video growth that produces 10% total growth today would produce 12% to 13% — and the deceleration would look far more like the cyclical account management gives than a structural one.