CSGP · PEAD ↓ 80

CoStar reported Q3 2026 EPS of $0.32 on 2026-10-27, beating the $0.28 consensus by $0.04 (+14.3%).

Print-day reaction was −5.0% versus the prior close, a sharp sell-the-news response despite the earnings beat. The overnight gap to the next open extended the damage by a further −6.3%, signalling no relief after hours and accelerating the downside. Over the following two trading days the stock drifted +8.6% off the lows, a partial recovery that nonetheless left cumulative losses intact. Cumulative abnormal return of −10.0% versus SPY.US firmly establishes a PEAD short read; the drift confirms the initial negative reaction, with the holding window running through 2027-01-22.