Gainers led losers 174 to 149 on Friday with 114 stocks unchanged on turnover of 3.3 billion shares worth 13.7 billion baht (333 million dollars).
The Thai baht closed at 41.02-04 to the dollar after 40.94-96 on Thursday, and at 48.56-59 to the euro, compared with 48.53-56.
"We saw window-dressing buying from local institutional investors. They rushed to buy some blue chip stocks before the end of this year," said Rakpong Chaisuparakul, a security strategist at KGI Securities.
Among major shares, Thailand's top energy firm PTT rose 2.00 to 226.00 baht while its subsidiary PTT Exploration and Production traded flat at 472.00.
Thailand's biggest commercial lender, Bangkok Bank, lost 1.00 to 105.00 but the second largest bank, Kasikorn Bank, gained 0.50 to 70.00.
Thai Airways put on 0.50 to 44.00 and Thailand's top mobile operator, Advance Info Service (AIS), gained 4.00 to 108.00 but Siam Cement, Thailand's largest industrial conglomerate, lost 2.00 to 244.00.