NEW YORK • The Japanese yen was set to end 2018 as the biggest winner against the US dollar among major currencies, after benefiting as investors sought out safety amid the year's uncertainties.

The yen outperformed as the British pound and euro faced headwinds from Brexit and Italy's budget crisis, while the US-China trade war and plunging oil prices pressured commodity-related peers such as the Canadian dollar.

The yen was up about 2 per cent on the year in Asian trading yesterday, to 110.45 per dollar. Meanwhile, the Japanese currency's share of global reserves rose to 5 per cent in the third quarter, the highest in 16 years.

If headwinds keep blowing in 2019, the yen could "win by default" to tack a fourth year on its streak of annual gains against the dollar, said Mr Shahab Jalinoos, head of forex trading strategy at Credit Suisse Group.

"News in Japan has been less negative than it has been in some other places, at least relative to original expectations, over the course of 2018," Mr Jalinoos said in a telephone interview. "And that allowed the yen to play the role of a safe asset of sorts within the framework of a generally negative year for risky assets."

The yen rose amid greenback weakness early last year, but gave back those gains after the dollar turned things around in April. After touching its weakest level of the year against the greenback in October, the yen advanced last month amid volatility in equity markets.

In the absence of factors that could inspire investor confidence in risky assets and global growth this year, Mr Jalinoos expects the yen to remain a favourite. The average forecast from a Bloomberg survey sees the yen strengthening to around 109 per dollar by end-2019.

Mr Marvin Barth of Barclays, however, said the Japanese currency could gain even more - to 107 yen per buck by end-2019. The yen advance this year will come as investors find themselves concentrated in US dollar risk and look for sources of diversification in the Japanese currency, he said.

"The yen is quite undervalued from a long-run historical perspective," the Barclays head of foreign exchange and emerging market macro strategy research said in a telephone interview. The forecast is "not a huge appreciation in the yen, but it is outperforming other currencies".

IG Asia's Singapore-based market strategist Jingyi Pan echoes forecasts for a stronger yen this year, saying: "With the array of worries including the uncertainty over the growth outlook expected to prolong, the haven trade may well be kept in favour.

"The eventual pause for the current Fed hike cycle could see yield differentials aiding the yen on its next leg up, something that had been absent in the past two years."

BLOOMBERG