Fair Isaac is trading 38.23% up at $923.04 after the October 9 regular-session close of $667.76, with no verified company-specific announcement or late-breaking catalyst explaining the after-hours move. - Coverage reports shares little changed after hours, leaving the spike unconfirmed by those sources. - Workforce restructuring and mortgage-scoring competition are significant background issues; coverage does not link either to the move. - Major U.S. indexes rose, but that does not explain the sharp move in the opposite direction.