The Bank of Thailand has prepared measures to tackle an influx of capital flows into local equity and bond markets and curb the baht's strength, a senior official says.
Some US$2 billion has flowed into the Thai stock market this year, half of that in July alone, said Chantavarn Sucharitakul, the assistant governor overseeing the financial markets operations group.
For the bond market, $3 billion has been poured into debt instruments this year, Mrs Chantavarn said.
"The baht rose 3.23% in value, with volatility of 4-5% since the beginning of the year," she said.
"The central bank has occasionally stepped into the market."
Thailand still has room for capital inflows and it could see rapid inflows and outflows in a certain period, she said.
Despite the persistent offshore fund inflows, foreign investors' holding in Thai bonds account for 8-9%, compared with 30-40% in other countries. Their holding in Thai equities has hardly changed and stands at 27%.
Capital inflows to Thailand have been apparent since Britain's vote to leave the EU in late June.
The shock vote added to global economic uncertainties and raised expectations that the central banks of major economies would launch further stimulus measures to shield the spillover effects and push back the US Federal Reserve's rate hike prospects.
The baht on Thursday hovered at 34.92 to the US dollar after touching a one-year high of 34.72 on Monday.
Mrs Chantavarn also warned those engaged in international trade to hedge against foreign exchange risks.
Exporters and importers account for a combined 20-30% of foreign currency hedging activities.
In the meantime, she said the central bank will soon award treasury-centre (TC) licences to two companies, while more than a dozen firms have enquired about licence applications.
Fourteen companies have sought TC licences from the central bank so far, she said, adding that six of them are Thai and the remaining eight are overseas firms.
PTT subsidiary PTT Exploration & Production and Thai Union Group Plc, the world's biggest exporter of canned tuna, are the latest companies to obtain TC licences.
With the licence, established TC companies can pool financial liquidity from firms under their group globally without seeking approval from the central bank for each cross-currency transaction or extend intercompany loans to subsidiaries with terms of more than one year, increasing the group's cash utilisation efficiency.