The Stock Exchange of Thailand (SET) is set to announce the new list of constituents for the SET50 Index in mid-June 2026, with the changes taking effect from July 1, 2026, through December 31, 2026. The data considered for this review period will be from June 1, 2025, to May 31, 2026, in accordance with established selection criteria.
According to Krungsri Securities (KSS), equities with the potential to be added or removed from the SET50 and SET100 indices for the second half of 2026 will be identified based on information from June 1, 2025, to April 16, 2026, with its anticipation offering a medium-to-high likelihood of accuracy compared to the upcoming announcement from the stock exchange.
For the upcoming cycle, four companies are expected to be added to the SET50 Index: Thai Airways International (THAI) with a 90% likelihood of inclusion, Bangchak Corporation (BCP) at 80%, MR. D.I.Y. Holding (Thailand) (MRDIYT) at 60%, and Thaifoods Group (TFG) at 80%.
However, the inclusion of MRDIYT remains uncertain, as its most recent free float is at 20.02%, close to the minimum requirement, while risks also remain, as certain shareholders may be classified as strategic partners, potentially causing the stock to fail the eligibility criteria.
Conversely, four stocks are projected to be excluded from the SET50 Index: BTS Group Holdings (BTS) with a 90% likelihood, Carabao Group (CBG) at 80%, Srisawad Corporation (SAWAD) at 80%, and Osotspa (OSP) at 60%.
Regarding the SET100 Index, six companies are anticipated to be added: THAI, MRDIYT, i-Tail Corporation (ITC), CK Power (CKP), WHA Utilities and Power (WHAUP), and Thaicom (THCOM). Set for removal from the index are Dohome (DOHOME), Jasmine International (JAS), Jaymart Group Holdings (JMART), Moshi Moshi Retail Corporation (MOSHI), SISB (SISB), and SCGJWD Logistics (SJWD).
Krungsri notes that, based on historical data from 2005 to 2026, over 60% of the stocks newly included in the SET50 Index tend to post price gains ahead of the effective date, while those removed often see price declines. On average, stocks added to SET50 deliver a positive return of 7.05% if bought around one and a half months before inclusion, while those removed fall by an average of 3.65%.
For the SET100 Index, stock prices typically trade in a narrow range about 45 days before the effective date, with removed stocks showing weakness. This is largely attributed to the relatively small size of passive funds tracking the index, resulting in limited market impact from portfolio revision.
Therefore, the recommended investment strategy is to avoid stocks likely to be excluded from SET50 and SET100 due to potential index fund reduction, and to speculate on the expected new additions to the SET50, specifically THAI, BCP, TFG, and MRDIYT.
KGI Securities (Thailand) (KGI) offers a similar view, analyzing 12 months of data up to April 2026. The brokerage forecasts that five companies are likely to be added to the new cycle of the SET50: BCP, ITC, MRDIYT, TFG, and THAI.
BCP and TFG are expected to move up from the SET100 Index, while ITC, MRDIYT, and THAI could debut in the SET50 Index, having not previously been constituents of the SET100. On the removal side, BTS, CBG, SAWAD, OSP, and Central Plaza Hotel (CENTEL) are at high risk of being excluded from the SET50 and being relegated to the SET100.
The majority of shares facing exclusion from SET50 have been negatively affected by declines in market capitalization, price weakness, and trading volume, key factors in the index selection criteria.
As for the investment outlook, KGI currently does not issue specific recommendations for BCP and TFG, but for the other three—THAI, ITC, and MRDIYT—the brokerage notes that THAI could face short-term pressure from rising jet fuel prices, which may prompt airlines, including the company, to reduce flight frequency in 2Q26.
On the other hand, ITC has shown robust 1Q26 performance, while MRDIYT’s profit is expected to have grown approximately 20% year-on-year, providing room for potential gains as it could be included in the SET50 Index.
