Singapore shares clocked gains on Monday, tracking mostly gains across the region, despite Donald Trump's decision to increase global tariffs to 15% after the US Supreme Court ruled the previous tariff mechanism as illegal.

The Straits Times Index (STI), a key benchmark for the Singapore Exchange, ranged between 5,014.36 and 5,041.33 throughout the day. It ended the session at 5,041.33, up 23.73 points or 0.5% compared to Monday's close.

In economic news, Singapore's core inflation fell to 1% year on year in January from 1.2% in December 2025, according to a joint release from the Monetary Authority of Singapore and the Ministry of Trade and Industry.

On the corporate front, shares of Wilton Resources (SGX:5F7) surged over 11% at the close as its subsidiary, Wilton Resources Holdings, sold 200 million shares in subsidiary PT. Wilton Makmur Indonesia (IDX:SQMI) via several off-market transactions for 40 Indonesian rupiah per share.

KTMG (SGX:XCF) slumped over 6%, with the integrated textile and apparel manufacturer expecting to book a loss for the second half of 2025 and the full year.

Meanwhile, shares of Raffles Medical (SGX:BSL) closed nearly 4% higher as its profit attributable to owners jumped 22% in the second half of 2025 to SG$38.5 million from SG$31.6 million a year earlier.