Tempus AI (TEM) is falling sharply in the session following its first-quarter 2026 earnings release on May 5, 2026, as investors reacted to a small revenue shortfall and a larger GAAP net loss even as the company posted rapid year-over-year growth. The move looks consistent with a post-earnings reset after expectations and positioning built ahead of the print.

Tempus reported Q1 2026 revenue of $348.1 million, up 36.1% year over year, with Diagnostics revenue up 34.7% and Data and Applications up 40.5%. However, the quarter included a wider GAAP net loss of $125.9 million, which the company said included $56.3 million of stock-based compensation expense and $32.3 million of unrealized losses on marketable securities—items that can weigh on headline profitability optics even when underlying revenue momentum is strong. �citeturn1search0turn1search3turn1search4

Alongside the quarterly results, Tempus increased its 2026 revenue outlook to $1.59–$1.60 billion and guided to approximately $65 million of full-year 2026 adjusted EBITDA. Despite the upward revision, the stock reaction suggests the market was priced for a cleaner beat or more upside, particularly after a notable run-up into the release. �citeturn0search10turn1search10turn1search1

Investors will likely focus on whether diagnostics volumes and the higher-margin data business can continue to scale while operating expenses moderate, and whether GAAP losses narrow as stock-based compensation and non-cash items become a smaller share of results. Any follow-on analyst estimate revisions and commentary around the revenue cadence implied by the raised full-year range could be the next catalysts for the stock.