Klaviyo, Inc. (KVYO) saw its stock price soar 6.53% during extended trading on Tuesday, following the release of its fourth-quarter financial results.

The significant surge was driven by the company reporting quarterly earnings and revenue that substantially exceeded analyst expectations. Klaviyo posted adjusted earnings per share of $0.19, beating the consensus estimate of $0.17 by 12.43 percent, and quarterly sales of $350.195 million, surpassing the $333.954 million estimate by 4.86 percent. This represents a 171.43 percent increase in earnings and a 29.62 percent rise in revenue compared to the same period last year.

Further bolstering investor sentiment, the company provided optimistic forward guidance. Klaviyo expects first-quarter revenue between $346 million and $350 million, above the consensus estimate of $343.7 million. For the full fiscal year 2026, the company raised its revenue outlook to a range of $1.501 billion to $1.508 billion, exceeding the analyst consensus of $1.48 billion. The strong performance was attributed to factors including successful AI platform integrations, significant international expansion with 42% revenue growth outside the Americas, and key enterprise customer wins.