Surface treatment maker Wei Tsuan Technology is still losing money in its core business, but buying interest driven by popular themes has lifted its share price by more than 50% since late August, leaving investors who chase the rally facing considerable risk.

• The company posted losses in both the second quarter and the first half of the year, and the losses were larger than in the same period last year.
• The share price, however, has climbed steadily, rising as much as a further 9% in intraday trading today, with volume expanding to nearly 9,000 lots.
• The reason for the gains is thematic: the company says it plans to move into co-packaged optics (CPO) and liquid cooling, two hot AI-related business opportunities.
• Its new plant in Thailand is scheduled to begin production by the end of this year, and is the main basis for the company's optimism about the future.
• Day trading accounted for close to 50% of turnover yesterday, and while foreign investors have been net buyers for three consecutive days, the amounts have been small, indicating that the shareholder base is tilted toward short-term speculation.

Outlook: With earnings yet to catch up with the themes, share price volatility may intensify in the near term.