Friday closes a chapter in investing history, with Warren Buffett stepping down as chairman of Berkshire Hathaway. In the post-Buffett era, the focus remains squarely on the artificial-intelligence rally.

Hyperscalers such as Alphabet and hardware suppliers like Intel are rising as investors shift their focus from interest-rate anxieties back to a strategy that has worked time and again this year. In Asia, chip makers including SK Hynix rose, sending the Kospi and other indexes higher.

A continued fall in oil prices is helping lift sentiment across markets. Brent crude futures are falling slightly to around $104 a barrel. The 10-year Treasury yield is up slightly to trade around 4.98%.

The mood marks a significant turnaround. Treasury yields and energy prices surged early this week on worries about oil-supply shortages, while stocks skidded after the leaders of three of the biggest AI companies called for development of the technology to be slowed down. Now, the Nasdaq is headed for a slight gain for the week, while Brent is on track to finish the week lower.

Meanwhile, in central banking news, the Bank of Japan raised its benchmark interest rate, as expected, to its highest level since 1995. Even so, dissent from two board members triggered a drop in the yen by raising doubts about the pace of further policy changes.