In mid-December, the Stock Exchange of Thailand (SET) will announce the list of stocks to be added to or removed from the SET50 and SET100 Indices for the first half of 2026. The changes will take effect from January 1, 2026, based on data from December 1, 2024, to November 30, 2025.
Krungsri Securities (KSS) revealed its projections for stocks likely to be added or removed from the new index constituents, using data from December 1, 2024, to October 27, 2025—about one month ahead of the official SET announcement.
The SET50 projection is considered highly accurate since most constituents have stable market capitalization and liquidity, while SET100 forecasts may have more variance due to faster changes in market caps within that group.
Speculative trading tends to increase in the 30–45 days leading up to the effective date. Historical data shows that stocks expected to be added to the SET50 typically yield an average return of 6–8% ahead of the official announcement, offering a short-term speculative opportunity.
Likely additions to the SET50 are Srisawad Corporation Public Company Limited (SET: SAWAD), 90% chance, and I-Tail Corporation Public Company Limited (SET: ITC), 90% chance. Likely removals from the SET50 are VGI Public Company Limited (SET: VGI), 90% chance, and Bangchak Corporation Public Company Limited (SET: BCP), 90% chance.
For the SET100 Index, likely additions are PTG Energy Public Company Limited (SET: PTG), Stecon Group Public Company Limited (SET: STECON), and GFPT Public Company Limited (SET: GFPT). Likely removals are Jasmine International Public Company Limited (SET: JAS), SISB Public Company Limited (SET: SISB), and WHA Utilities and Power Public Company Limited (SET: WHAUP).
Even though Delta Electronics (Thailand) Public Company Limited (SET: DELTA) remains in both the SET50 and SET100, its index weighting will be reduced again due to the capping rule, which limits a single stock’s weight to no more than 10% of the index’s total market value. This means SET50 Index passive funds must sell DELTA to reduce its proportion, resulting in approximately THB 1.6 billion in potential selling pressure, which could temporarily weigh on the share price.
However, DELTA remains a stock with low liquidity but disproportionately high market capitalization (High Market Cap but Low Float), causing it to be rebalanced every half year and making it a closely watched stock by both local and foreign investors.
According to KSS, studies of historical data from 2005–2024 reveal that stocks being added to the SET50 deliver an average gain of +6.97% in the one month ahead of the official announcement, with a 70% chance of price increase in such cases. Conversely, stocks being removed from the index typically fall an average of 2.8% in the same period, indicating strong speculative behavior among investors anticipating the effective date.
The securities firm recommends that investors avoid stocks likely to be removed from the SET50/SET100 due to the risk of index fund selling pressure and suggests “short-term speculation” in stocks likely to be added, particularly SAWAD and ITC, which have strong fundamentals and show consistent early price appreciation signals.
