EPAM Systems is trading 22.89% higher at $137.14 after-hours; the catalyst remains unconfirmed. - Shares closed at $111.60 on September 22, 2026; no company-specific announcement, earnings release, or major corporate event was identified for that date. - The Nasdaq Composite gained 0.61%, but that moderate market move does not explain the unusually large after-hours jump. - Available coverage described the catalyst as unconfirmed; delayed news, thin liquidity, or an unverified report may be factors.