Thailand's stock index fell more than 6 percent on Wednesday and the baht skidded, a day after police warned of a Bangkok bomb plot and on weekend news that 88-year-old King Bhumibol Adulyadej's health was in an unstable condition.
The Stock Exchange of Thailand fell as much as 6.9 percent at one point to its lowest since March 1, led by shares in the aviation and tourism industries. It had been down 2.6 percent at midday.
The baht fell to as low as 35.88 to the dollar, its lowest in more than eight months.
Thailand's king, the world's longest reigning monarch, is in an unstable condition after receiving haemodialysis treatment, the palace said on Sunday.