Sarath Ratanavadi Retains Top Spot Despite 20 Per Cent Valuation Drop
For the seventh consecutive year, Sarath Ratanavadi, Executive Director and CEO of Gulf Development Public Company Limited (SET: GULF), has been crowned the wealthiest Thai stock billionaire in the 2025 ranking. The annual ranking, compiled by Money & Banking Magazine in collaboration with the Faculty of Commerce and Accountancy, Chulalongkorn University, is based on individual shareholdings of at least 0.5 per cent in listed companies as of the September 30, 2025, cutoff date.
Despite retaining the coveted top position, Sarath Ratanavadi saw the total value of his shareholdings decline significantly, falling by THB 50,349.43 million, or 20.95 per cent, to a total value of THB 189,992.47 million. This substantial decrease was primarily attributed to the falling share price of GULF, his main holding.
On the calculation date, GULF’s share price was recorded at THB 43.50 per share, representing a sharp 23.68 per cent drop from the THB 57.00 per share price recorded in the 2024 ranking. The bulk of his wealth, valued at THB 189,684.32 million, stems from his 29.19 per cent stake in GULF.
Additionally, Sarath Ratanavadi holds a smaller 0.65 per cent stake, valued at THB 308.15 million, in i-Tail Corporation Public Company Limited (SET: ITC), a major pet food manufacturer and subsidiary of Thai Union. This consistent decline in valuation reflects the general market conditions and the volatility inherent in even the largest single-stock positions.
However, a significant measure of his long-term financial resilience is the fact that over the entire seven-year period of holding the top title, his shareholding value has never once dropped below the THB 100 billion mark in any given year, underscoring the enduring scale of his investment.
Heirs And Tycoons Dominate The Elite Shareholder Ranking
The 2025 Thai Stock Billionaires Ranking confirms the enduring dominance of major business heirs and established industry tycoons in the nation’s capital markets, with the top positions remaining firmly held by familiar names despite widespread market value declines. The second wealthiest shareholder is Niti Osathanugrah, a prominent investor and heir to the Osotspa business empire, who successfully retained his second-place position from the previous year.
Niti’s total shareholding was valued at THB 47,313.08 million, marking a decline of THB 12,159.34 million, or 20.45 per cent, closely tracking the percentage drop experienced by Sarath Ratanavadi. His investment strategy remains diversified, spread across the same ten companies as the previous year, including significant stakes in Osotspa Public Company Limited (SET: OSP), Minor International Public Company Limited (SET: MINT), and Home Product Center Public Company Limited (SET: HMPRO).
Maintaining his third-place ranking is Dr. Prasert Prasarttong-Osoth, affectionately known as “Mor Sert,” the founder and owner of the Bangkok Hospital Group and Bangkok Airways. Dr. Prasert holds total shareholdings valued at THB 33,062.33 million, representing the steepest percentage decline among the top three at 34.74 per cent, or THB 17,602.89 million, reflecting volatility in the healthcare and aviation sectors.
His core holdings include a 9.18 per cent stake in Bangkok Dusit Medical Services Public Company Limited (SET: BDMS) and an 11.38 per cent stake in Bangkok Airways Public Company Limited (SET: BA). The consistent presence of these established figures—including Sarath Ratanavadi—at the pinnacle of the ranking highlights a crucial characteristic of the Thai market, where generational wealth and the control of major listed conglomerates often dictate the distribution of stock wealth.
Financial Sector Founders Show Market Resilience
The fourth and fifth positions in the 2025 ranking are occupied by the co-founders of Muangthai Capital Public Company Limited (SET: MTC), demonstrating the significant wealth creation achieved within the fast-growing non-bank finance sector and their relative resilience during a period of market contraction. Daonapa Petampai is ranked as the fourth wealthiest shareholder, retaining her position with a major 33.96 per cent stake in MTC, valued at THB 29,160 million.
While she also saw a decline in her shareholding value, the 18.18 per cent drop was slightly less severe than the declines experienced by the top three shareholders, indicating comparatively lower volatility in the finance company’s stock compared to large industrial or healthcare conglomerates. Following closely behind, Chuchat Petampai secures the fifth position, also retaining his rank with total shareholdings valued at THB 28,878.71 million, experiencing an 18.52 per cent decline.
His portfolio is concentrated, primarily featuring a 33.49 per cent stake in MTC, alongside a minor 2.32 per cent holding in XSpring Capital Public Company Limited (SET: XPG). The sustained presence of both Daonapa and Chuchat in the top five, with core wealth tied to MTC, reinforces the strong performance narrative of Thailand’s microfinance and retail lending sector.
While the overall wealth of the top billionaires, including Sarath Ratanavadi, decreased due to the GULF stock price correction and general market downturns, the founders of MTC successfully maintained their elite status. Their retention of high ranking underscores the stability of their core asset and the ongoing profitability of financial services catering to domestic demand, confirming that large industrial holdings and consumer finance remain the primary engines of ultra-high net worth accumulation in the Thai capital market.
Market Concentration Risk And Thai Capital Dynamics
The 2025 Thai Stock Billionaires Ranking, dominated by Sarath Ratanavadi and a handful of other entrenched tycoons, provides a quantitative indicator of significant market concentration risk within the Stock Exchange of Thailand (SET). The fact that the top five shareholders saw their collective wealth decline by an average of approximately 23 per cent, largely tracking the correction in GULF’s share price and broader market volatility, demonstrates that the SET Index’s performance can be disproportionately influenced by the valuation cycles of a small number of controlled, large-cap companies.
This high concentration suggests that changes in regulatory policy, sector-specific risk (such as the energy market influencing GULF), or corporate governance shifts within these few conglomerates can generate systemic risk across the entire exchange, affecting retail and institutional investor confidence. The valuation disparity between industrial holdings (GULF) and consumer finance (MTC) further highlights capital rotation dynamics; while Sarath Ratanavadi’s GULF-based wealth suffered from external or long-term growth concerns, the founders of MTC showed relative stability, suggesting investors maintained stronger conviction in domestic consumption and credit growth.
For regional investors, this ranking underscores a key characteristic of emerging ASEAN markets: wealth is often anchored to controlling stakes in family-run conglomerates rather than highly diversified portfolios, making the market less about broad economic performance and more about the trajectory of these key corporate families. This structure necessitates a due diligence focus on corporate governance and succession planning within these specific top-tier companies, as their performance directly impacts a substantial portion of the nation’s listed market capitalization.
