🟢 Klaviyo is trading 4.54% up in after-hours trading with no confirmed September 16 company-specific catalyst

Klaviyo is trading 4.54% up at $16.98 in after-hours trading after closing at $16.24 on September 16, 2026, with no confirmed same-day company-specific catalyst.

• No confirmed September 16 announcement, earnings release, or analyst action explains the rebound.
• Latest identifiable news was Klaviyo’s September 9 AI-platform expansion at its annual customer conference, appearing stale rather than a same-day catalyst.
• Broader markets were mixed, while higher rates and Fed uncertainty pressured growth stocks.