Asian shares cautious, dollar gives back gains

Asian shares were cautious on Wednesday as investors looked ahead to earnings results from AI darling Nvidia where the risk of disappointment is high, while the dollar gave back a little of its recent bumper gains.

The world's most valuable company Nvidia will report its third-quarter results after the bell. Shares already climbed 4.9 per cent overnight and options imply a big move of almost 9.0 per cent either direction in the $US3.6 ($A5.5) trillion stock often seen as a barometer for the tech sector's shift to AI.

Nasdaq futures rose 0.2 per cent on Wednesday on top of a 1.0 per cent jump overnight. MSCI's broadest index of Asia-Pacific shares outside Japan was flat and Tokyo's Nikkei slipped 0.3 per cent.

Bitcoin last held at $US91,914 ($A140,734), having broken above $US94,000 ($A143,928) for the first time overnight on expectations that US President-elect Donald Trump's administration will be crypto-friendly.

In China, the central bank held the benchmark lending rates steady as widely expected. China's blue chips fell 0.2 per cent while Hong Kong's Hang Seng index edged up 0.1 per cent.

"NVDA was naturally the key topic on everyone's mind. Big-picture, a nice beat seems widely anticipated tomorrow," said Joshua Meyers, executive director at JPMorgan.

"FY26 expectations have become quite ebullient, a worry that comes up increasingly in conversations ... Jensen's commentary on the call will be particularly important to level-set expectations (or not)."

Overnight, investors were rattled by Ukraine's use of US missiles to strike Russia, with Russia lowering the threshold for a possible nuclear strike, although those fears seem to have abated a little.

They are also watching the Treasury secretary pick from Trump as he assembles his governing team. CNN reported Trump can announce the decision as soon as on Wednesday.

Safe-haven currencies such as the Japanese yen and the Swiss franc gained briefly, as well as Treasuries. Benchmark 10-year note yields were last up 1.0 bp at 4.3903 per cent, having fallen 4.0 basis points, still some distance away from a five-month top of 4.505 per cent.

The yen held at 154.96 per dollar, having hit a one-week high of 153.28 per dollar overnight. The US dollar held onto the overnight losses at 106.19, off from its recent one-year top of 107.07.

Oil prices rose slightly on Wednesday, building onto the small gains overnight. US West Texas Intermediate crude futures rose 0.2 per cent to $US69.53 ($A106.46) a barrel, having ended Tuesday just 0.3 per cent higher

Gold climbed for a third consecutive session, up 0.2 per cent to $US2,637.95 ($A4,039.10) per ounce.