Why is Five9 stock tumbling today?

Five9 stock tumbled 16.7% in pre-open trading to reach $28.44 after the cloud contact center software company delivered a Q4 earnings outlook that disappointed Wall Street, overshadowing an otherwise strong Q3 2026 report.

Q3 adjusted EPS of $0.82 beat analyst estimates of $0.80, and revenue reached $323.3 million, up 13% year-over-year, exceeding consensus.

However, Q4 adjusted EPS guidance of $0.88 to $0.92, with a midpoint of $0.90, fell significantly short of analyst expectations. Management attributed the full-year EPS revision downward to timing revisions, planned organizational structure changes, and a higher diluted share count resulting from a higher-than-expected share price.

Adding to investor unease, Five9 simultaneously announced a major acquisition. Five9 entered into a definitive agreement to acquire Level AI, an AI-native platform for the entire customer journey.

The deal is valued at $325 million in cash, and the company confirmed that its guidance does not include any contribution from Level AI.

The reaction, with the stock already sharply lower after the close, reflects the combination of below-consensus guidance, adjusted gross margin slipping to 61.7% from 62.8%, and the $325 million cash outlay for Level AI arriving in the same release.

On the analyst front, Barclays maintained its Overweight rating on Five9 but lowered its price target to $38 from $40, reflecting the softer forward outlook.

From a broader market perspective, the NASDAQ is up 1.84% today, underscoring that Five9’s sharp decline is entirely company-specific rather than a reflection of sector-wide or macroeconomic pressure.

The S&P 500 is also modestly positive, further isolating the post-earnings reaction as the sole driver of today’s move. With 14.33% of Five9’s float sold short and short interest having recently increased by 6.20%, the stock was already under elevated bearish pressure heading into the print.

Taken together, a rare combination of below-consensus forward EPS guidance, a meaningful compression in adjusted gross margins, and a large cash acquisition that will weigh on the balance sheet created a perfect storm for sellers.

While Five9’s Q3 operational results demonstrated continued momentum — subscription revenue grew 16% year-over-year in the third quarter — the market’s focus has firmly shifted to the earnings trajectory and the integration risk associated with the Level AI deal, driving the stock to its current pre-market level of $28.44, well within its 52-week range of $13.29 to $40.00.