The Stock Exchange of Thailand climbed 0.47%, or 8.14 points, on Monday.
Total trading value was 34.6 billion baht, with 6.3 billion shares changed hands.
The SET50 index advanced 0.64%, or 7.22 points, to 1,135.70 in trade worth 19.2 billion baht.
MAI gained 0.36%, or 1.92 points, to 542.17 in transactions worth 2.2 billion baht.
Institutional investors were net buyers of 1.6 billion baht worth of shares, followed by foreigners (1.5 billion baht) and brokers (24.3 million baht). Individual investors sold 3.1 billion baht.
Year-to-date, institutional investors were net buyers of 98.5 billion baht, followed by brokers (18.9 billion baht). Retail investors were net sellers of 91.3 billion baht, followed by foreigners (26 billion baht).