The Stock Exchange of Thailand Index rose 10.21 points from Thursday to close at 1,274.28, a decrease of 3% from the previous Friday's close of 1,314.63. Turnover was only 21.56 billion baht, with 2.57 billion shares traded.
The local market ended the first month of 2014 down 1.8% from the end of 2013.
The biggest price swings in Thai stocks since the country imposed capital controls in 2006 are turning some big fund managers into buyers on speculation that corporate profits will weather the political turmoil.
Invesco Asset Management, Aberdeen Asset Management and BBL Asset Management, which oversee a combined $1.1 trillion, say market swings caused by anti-government protests and $344 million of foreign outflows this month have created buying opportunities among oil producers and telecom stocks.
Despite all the political volatility, analysts' estimates compiled by Bloomberg show SET Index profits will probably climb 21% during the next 12 months.
"We have been buying more in Thailand," said Abdul Jalil Abdul Rasheed, a Singapore-based investment director at Invesco. "We are invested in companies, not countries."
However, foreign investors overall were net sellers on Friday of 2.37 billion baht worth of Thai shares, bringing their net sales for the month to 13.66 billion baht.
Local institutions were net buyers of 2.98 billion baht and retail investors bought 72 million, while brokers were net sellers of 680.6 million baht.
Elsewhere, European shares opened lower as they struggled to shake off the difficulties that have spread from emerging markets this week. As a result, markets in Europe were heading for their first monthly decline since August.
Britain's FTSE 100 and France's CAC 40 were down 0.3% and Germany's DAX was off 0.8% as weaker than expected retail sales and pressure on Deutsche Bank hit sentiment.
Lunar New Year celebrations meant many bourses in Asia were closed, but others slipped as fears about the impact of the Federal Reserve's stimulus withdrawal offset upbeat US growth data.
Japan's Nikkei stock average reversed sharply and ended down 0.6% as a resurgent yen, combined with data dousing hopes of more stimulus from the central bank, left the index with its third worst January in 50 years.
In Bangkok, the SET50 index of blue chips ended at 866.34 points, up 8.84 points, with total trade value of 18.6 billion baht. The SETHD index of high-dividend shares rose 12.12 points to 1,054.10, with turnover of 10.39 billion baht. The Market for Alternative Investment gained 0.70 to 351.74, with transaction value of 391.7 million baht.
The five most active shares by value were BBL, rising 2.50 baht to 171.50; PTTEP, down 3 baht to 153; KBANK, down 1 baht 170; JAS, up 20 satang to 7.05 baht; and PTTGC, up 1.75 baht to 71.25.
In the currency market, the baht fell to 33 to the dollar as global funds continued to pull money from local assets amid concern the election will turn violent.
Market data showed that foreign investors sold $499 million more Thai stocks and bonds than they bought this week through Thursday. Most Asian currencies fell this week as the Federal Reserve further cut the stimulus that has buoyed emerging markets.
"We have seen demand for the dollar on concern about the situation before the election," said Disawat Tiaowvanich, a foreign-exchange trader at Bangkok Bank.
"There’s the Fed's tapering that caused emerging-market selloffs and plus, we have this political unrest. No one would like to put money in Thailand unless we have solutions."
The baht was trading late Friday in Bangkok at 33.00 to the dollar, compared with 32.96/33.00 on Thursday and 32.86/91 a week earlier.