Macau casino stocks dropped Monday after the city reported more than two dozen Covid-19 illnesses over the weekend, its first epidemic in eight months.
More border restrictions from mainland China would further damage tourism in the world's biggest gambling market.
Macau's six biggest casino operators plummeted as much as 5%, bringing their year-to-date losses to 28%. Sands China Ltd. fell 8.3%, while Wynn Macau Ltd. fell 7%.
Melco Resorts & Entertainment Ltd.'s 5.25 percent note due 2026 slid 3.6 cents to 73.7 cents, on track for a new closing low.
The authorities tested people from Sunday through Tuesday and identified 34 positive cases by Monday morning. Closed schools and businesses.
Officials have urged restaurants, bars, and casinos to cease dining-in services or activities to decrease visitors.