City Holders has introduced a daily combo event starting October 27, 2025, allowing players to earn up to 7.5 million gold coins by using specific card combinations. The event, detailed by BitJie Wang, includes a quiz with answers such as Stockholm, Japan, and Bitcoin. Players can access the combo feature in the 'Your City' section to select top-ranked cards and claim rewards. The game integrates blockchain technology, with plans to issue a token and collaborate with exchanges. Developers emphasize the importance of financial safety and understanding trading rules for participants.