Vietnam stocks plummeted nearly 4 percent on Monday, extending a market rout after a near 7 percent decline over the last two weeks, while most other stock markets in the region slipped as U.S. bond yields rose to a multi-year peak.
The Vietnam index, the only double-digit percentage gainer in Southeast Asia this year as of Friday's close, marked broad-based losses, led by financials and energy stocks.
Vietcombank and Petrovietnam Gas Joint Stock Corp each ended 6.9 percent lower.
Most other Southeast Asian stock markets slipped, in line with broader Asia, as U.S. 10-Year treasury yields hit 2.968 percent, their highest since January 2014, a jump widely seen as a technical shift in the market following a large selloff of bonds.
The Thai index shed 0.6 percent as energy and financial stocks fell. Oil and gas company PTT Pcl closed 2.7 percent lower while financial services provider, Siam Commercial Bank PCl, dropped 1.8 percent.
Philippine shares ended marginally lower as financial stocks weighed on the benchmark.
BDO Unibank Inc was the biggest drag on the index and slipped to its lowest close in over five months. The bank confirmed it deferred a deal to sell a 40 percent stake in rural bank One Network Bank to a unit of U.S.-based global private investment firm TPG.
The Indonesian stock market slipped 0.47 percent, dragged down by consumer stocks, healthcare and financials.
The country's index of 45 most liquid stocks fell 0.68 percent.
Financials and telecom stocks dragged the Malaysian index 0.4 percent lower. Index heavyweights CIMB Group Holdings and fell 0.8 percent, while DiGi.Com closed nearly 1 percent lower.
Singapore shares were the sole gainers in the region, erasing earlier losses in the session to close 0.17 percent higher.
Singapore's headline consumer price index (CPI) rose 0.2 percent in March from a year earlier, compared with a 0.5 percent growth in February, data showed on Monday.