The baht slid to its lowest in more than a year on Wednesday after the Bank of Thailand (BoT) promised to keep monetary policy loose and slashed its 2021 economic growth forecast, citing a hit to its tourism sector.
The BoT held interest rates steady at 0.5% and lowered growth forecasts for this year to 1.8%, versus the previous 3%, as the economy reels from coronavirus-linked restrictions that have ravaged tourism.
Thai stocks flatlined near three-week lows, while the baht dropped 0.5%, its biggest one-day fall since mid-March and its eighth straight day in the red. The currency is down more than 6% year-to-date.
"The poor prospects for the economy mean that monetary policy will need to remain loose for a long time to come... the tourism sector remains on its knees," Gareth Leather, senior Asia economist at Capital Economics told clients.
Most other Asian currencies rose against a retreating greenback, after senior Federal Reserve officers assured that the central bank would not hike benchmark rates too quickly and provide support to allow the economy to fully recover.
The Korean won and the Philippine peso rose 0.5% and 0.3%, while the Malaysian ringgit also advanced.
Emerging market assets, generally considered riskier investments, have suffered broad losses since last week after the Fed indicated it may raise rates earlier than expected and signalled tapering in its bond-buying programme.
Singapore shares rose, while Indonesian and Malaysian indexes retreated.
Philippine stocks ended higher, helped by the likes of Ayala Land and International Container Terminal Services.
Eyes are on the country's central bank policy meet slated for Thursday, where it is expected to leave its benchmark interest rate at a record low for a fifth straight policy meeting, as per a Reuters poll.
A resurgence in Covid-19 infections in some parts of the country has reinforced the need for continued policy support, as mobility restrictions have hurt businesses.