Singapore's closed marginally lower on Friday, tracking regional losses with markets reacting to uncertainty regarding Donald Trump's policy decisions, which also resulted in higher oil prices and lower GDP projections.

The Straits Times Index (STI), a key benchmark for the Singapore Exchange, ranged between 3,911.61 and 3,936.43 throughout the day. It ended the session at 3,926.45, down 4.04 points or 0.1% compared to Thursday's close. YZJ shipbldg rose 5%, Thomson Medical up 4%, While ST Engineering down 4%.

In company news, shares of Capital World (SGX:1D5) plunged 50% after three employees of its subsidiary, Capital City Property, were questioned by the Malaysian Anti-Corruption Commission.

Abundance International (SGX:541) surged nearly 16% at the close after its subsidiary, Abundance Investments, has agreed to dispose of its entire 12.74% stake in Shanghai Sunrise Polymer Material to Changzhou Ju Ke Emerging Industry Venture Capital Fund Partnership Enterprise.

Meanwhile, Keppel Infrastructure Trust (SGX:A7RU) was up over 1% at the close after it completed the sale of its 50% stake in Philippine Coastal Storage and Pipeline.