The SET Index closed 26.36 points lower on Thursday, weighed down by a broad sell-off in the technology sector and significant selling pressure from large-cap stocks.
Delta Holdings (DELTA) emerged as the primary drag on the benchmark, accounting for approximately 21 of the index's total decline.
The move reflects continued vulnerability in growth-oriented segments amid broader market caution.
The decline in the SET Index mirrors weakness seen in global equity markets earlier in the week.
US equity markets closed lower on Tuesday as broad selling in the technology sector dragged down the S&P 500 and Nasdaq Composite.
The decline was led by Meta Platforms, which saw its shares fall sharply following reports of regulatory scrutiny and slowing user growth.