This story is part of Forbes’ coverage of Thailand’s Richest 2025. See the full list here.

Sliding shares of Siam Global House, which owns the Global House chain of building-materials and DIY stores, nearly halved the net worth of founder Witoon Suriyawanakul to $475 million. Net profit slumped 11% in 2024 to 2.3 billion baht ($71 million) while revenue stagnated at 33 billion baht amid weak consumer spending and higher costs related to distribution, staffing and store openings. In the first quarter of 2025, tepid same-store sales growth slashed net profit by 14%.

The company, run by Witoon as CEO, plans to open seven new outlets in Thailand in 2025, taking the total to 99, including two in Cambodia. However, further regional expansion is on hold for now: In December, the company’s joint venture to launch the DIY chain in the Philippines with Manila-based Cosco Capital, owned by rich listers Lucio and Susan Co, was called off. In an April report, Suttatip Peerasub, an analyst at Maybank Securities (Thailand), predicted flat net profit and revenue for 2025.