Shares of advertising technology (adtech) company DoubleVerify (DV -36.03%) sank on Friday after the company reported financial results for the fourth quarter of 2024. As of 3:40 p.m. ET, DoubleVerify stock was down 38% and had hit an all-time low during the trading session.

DoubleVerify's financial results didn't satisfy investors

DoubleVerify uses analytics to help advertisers know whether their spending is accomplishing what it's supposed to. During 2024, the company's revenue was up 15% year over year, a respectable growth rate. But Q4 revenue of $191 million was only up 9% and below management's prior guidance of revenue of at least $194 million.

For 2025, DoubleVerify is guiding for 10% revenue growth, continuing a multiyear deceleration trend. For perspective, the company's revenue was up 36%, 36%, and 27% in 2021, 2022, and 2023, respectively. Its 15% growth in 2024 and projected 10% growth in 2025 continues to slip slower and slower. And slower growth isn't what investors want from a niche adtech stock.

Part of the reason why the growth rate is slowing

Part of the problem for DoubleVerify appears to be spending with some of its largest customers. Management said that one of its biggest spenders dramatically cut back during Q4, to the point that management is excluding this customer completely from its 2025 guidance. And this incident wasn't isolated. Six big DoubleVerify customers cut back in 2024.

DoubleVerify's business isn't without its merits. The company had $52 million in net income in 2024, it has over $300 million in cash and short-term investments, no debt, and it's seemingly well-positioned for an increasingly digital advertising market. However, as long as it's having spending problems from big customers, DoubleVerify stock might struggle to give investors confidence in its long-term upside potential.