Thai Billionaire ‘Sarath Ratanavadi’ Adds 2.42 Million of GULF Shares Into Portfolio

Thai billionaire Sarath Ratanavadi has boosted his holding in Gulf Development Public Company Limited (SET: GULF) by purchasing 2.42 million shares, pushing his voting stake in the power and utilities company to roughly 29.20%. The acquisition of 2,415,600 common shares was executed on 14 September 2026 at an average price of 60.75 baht per share, for a total transaction value of approximately 146.75 million baht.

"Report of Changes in Executive Securities Holding"

The transaction was carried out on the Stock Exchange of Thailand via the Auto Matching system through Bualuang Securities Public Company Limited. Following the purchase, Sarath Ratanavadi's total shareholding in GULF rose from 4,360,734,893 shares to 4,363,150,493 shares, consolidating his voting rights at 29.20% of the company.

Transaction details

• Transaction date: 14 September 2026
• Number of shares acquired: 2,415,600 (approximately 2.42 million)
• Average price per share: 60.75 baht
• Total transaction value: ~146.75 million baht
• Execution method: Auto Matching on the Stock Exchange of Thailand via Bualuang Securities Public Company Limited
• Shareholding change: from 4,360,734,893 to 4,363,150,493 shares
• Resulting voting stake: 29.20%

Sarath Ratanavadi is the chief executive officer of Gulf Development Public Company Limited, a major player in Thailand's energy sector. The recent purchase was disclosed in a Form 59 filing, the official "Report of Changes in Executive Securities Holding" used to notify regulators and investors of insider movements. The filing confirms the precise figures for the acquisition and the updated shareholdings following the trade.

GULF, listed on the SET under the ticker GULF, has been actively expanding its generation portfolio in recent years. While this specific filing does not disclose strategic rationale, insider purchases of this scale are closely watched by market participants for signals about management confidence in the company's outlook or expectations for future share price performance.

Outlook

The incrementally increased stake takes Ratanavadi closer to the 30% threshold, a level that could carry governance implications depending on Thai corporate rules and any future moves by the investor. At 29.20% voting power, he remains a dominant individual shareholder, preserving substantial influence over corporate decisions and strategic direction.

Market observers will monitor subsequent disclosures and any further buying or selling activity. Additional insider purchases could indicate continued conviction in GULF's growth prospects, while disposals or a change in the concentration of holdings would prompt questions about shifts in strategy or liquidity needs. For now, the 14 September transaction is a clear signal of continued personal investment by GULF's CEO into the company he leads.