The sharemarket was flat in quiet trading before a US holiday and the outcome of a two-day policy meeting of the Bank of Japan.

US markets were due to be closed for Martin Luther King Day.

The benchmark S&P/ASX 200 rose 0.1 per cent to 4777.5 points after being confined to a narrow range of 4762.6-4779.7. The index hit a 20-month high of 4787.2 last week, having risen 10 per cent since mid-November.

The market was cautious after pricing in expectations of further policy stimulus from the BoJ as well as an improved worldwide growth outlook stemming from recent better-than-expected economic data in China and the US. "I remain bullish on equities but I wouldn't be buying now because a lot has been priced into the market," IG chief market strategist Chris Weston said.

"Valuations are still reasonable, but we've had a good run and domestic earnings season is coming up. The BoJ would have to adopt negative interest rates or commit to unlimited quantitative easing in order to provide a further bullish catalyst for risk assets in the short term.