Costco Q3 Earnings Beat Revenue But Stock Drops 4.7%: The $5.3 Billion Membership Machine That Wall Street Still Can't Price Right Costco Q3 2026 earnings beat Wall Street's revenue estimate by nearly $1 billion, with $70.53 billion in revenue and 9.8% same-store sales growth. Yet COST stock fell 4.7% after hours as a five-cent E... Economy Finance Stock Market 29-May-2026 0 280