At one time, the Stock Exchange of Thailand index hit 1,602.28 points. Turnover was Bt50 billion.
Asia Plus Securities expects the index to test the 1,602 points-level again next week, as the market is now boosted by renewed investment in small-cap stocks. Investment should be soon shifted to big and mid-cap stocks, which normally attract investment from institutional investors before the end of the year.
Throughout Asia, stocks were mixed in lacklustre trade as oil prices hit a new four-year low ahead of a pivotal Opec meeting expected to maintain the cartel's production levels despite a huge glut.
Tokyo lost 0.78 per cent as a stronger yen took the wind out of the market ahead of the Thanksgiving holiday, which will see US markets closed Thursday and open for shortened trade on Friday.
Hong Kong slipped 0.45 per cent or 107.70 points to 24,004.28, with energy stocks falling ahead of a decision by the Organization of the Petroleum Exporting Countries (Opec) on quotas.
"Oil prices continued to struggle in Asia with investors unconvinced output cuts can be agreed to support prices," said IG in comments carried by Dow Jones.
The Nikkei 225 index at the Tokyo Stock Exchange shed 135.08 points to finish at 17,248.50, while the Topix index of all first-section shares fell 1.03 per cent, or 14.50 points, to 1,391.90.
"The US holiday break is going to suppress participation levels through Friday, and with the dollar looking top-heavy, more air could come out of the stock market," Sumitomo Mitsui Banking Corp. strategist Daisuke Uno told Dow Jones Newswires.
In forex markets, the greenback slipped to 117.29 yen, from 117.72 yen in New York, on the back of mixed US economic figures.