The Stock Exchange of Thailand index stood firmly above 1,500 points on Monday, thanks to solid gains in western markets.
More accommodating monetary policies have attracted funds to Asian emerging markets even as concerns over the debt ceiling in the US and public debt in Europe have not subsided.
The index rose 0.48% on Monday to close at 1,506.37 points in heavy trade worth 54 billion baht.
Charamporn Jotikasthira, president of the SET, said the overall market remains positive due to numerous factors such as listed firms' earnings growth of around 12-14% this year. But he warned baht appreciation might put pressure on export-dependent sectors.
Mr Charamporn believes the Bank of Thailand has measures to cope with heavy fund flows.
Regulators continued to warn investors about risks in some 70 stocks, especially those with price-to-earning ratios (P/E) of more than 40 times.
Chai Jirasereenupraphand, a strategist at Capital Nomura Securities, said Thai energy stocks rallied in line with commodities prices and speculation on their 2012 earnings.
Arpaporn Sawangpak, research manager at DBS Vickers Securities (Thailand), said liquidity is abundant in the world market as the US Federal Reserve purchased assets worth up to $104 billion, resulting in more new money coming into the market than expected.