SYDNEY/LONDON - Global shares ‍fell for a fourth day on ‍Wednesday and some measures of market stress remained high after a rout in global bonds and U.S. threats to acquire Greenland kept investors on edge ​ahead of President Donald Trump's Davos speech.

Fears of foreign selling of U.S. assets - the so-called "Sell America" trade that emerged after last year's "Liberation Day" tariff announcements in April - gripped markets as Wall Street ⁠tumbled more than 2% overnight and the U.S. dollar suffered its biggest fall in over a month.

That sent investors fleeing to the safety of gold, which surged 2.1% to a new record ⁠of $4,865 ‌an ounce.

"The 'sell America' trade was the driving force behind major market moves overnight, as investors looked to reduce exposure to the U.S., seen by many as an unreliable partner pursuing self-defeating policies," said Mantas Vanagas, a senior economist at Westpac. Trump has doubled down on his rhetoric over Greenland, saying there was "no ⁠going back" on his goal to control the island, refusing to rule out taking it by force. Crucially for markets, his threat of tariffs on Europe has also rekindled fears of a global trade war.

The European Union will convene an emergency summit in Brussels on Thursday to discuss the matter, with the long-standing U.S.-EU alliance clearly at risk.

All eyes are now on the World Economic Forum in Davos, where Trump is due to deliver a speech later in the day that could either calm or ⁠inflame tensions with Europe.

MSCI's All-World index was down ​0.12%, heading for a fourth daily drop, as was Europe's STOXX 600 index , which is laden with export-focussed stocks, such as defence, pharma and tech, that have come under pressure as the risks of additional U.S. ‍tariffs have increased.

The VIX index, which measures demand for protection against big swings in the S&P 500, edged down to 19.19, but was still within sight of Tuesday's two-month highs. The index is often used as a proxy ​for investor nervousness.

Wall Street futures were up around 0.3% , suggesting a modest rise at the opening bell later.

"The key question is whether dip buyers step in to support early weakness, or whether traders see developments that justify taking risk down further," Pepperstone head of research Chris Weston said.

BONDS ATTEMPT RECOVERY

The global bond market was still reeling from a brutal selloff, having been caught up in a perfect storm of worries over exposure to U.S. assets and a surge in Japanese government borrowing costs.

At the epicentre were long-dated Japanese sovereign bonds, which endured their most aggressive selloff in nearly 25 years on Tuesday, as fears grew over increased government spending under Japanese Prime Minister Sanae Takaichi. U.S. 30-year Treasury yields neared the 5% threshold for the first time since September, while German government bond yields also rose sharply. By Wednesday, Japanese bonds rallied in price as buyers returned, which almost entirely reversed the previous day's rise in yields. A similar dynamic played out across U.S. Treasuries, where 30-year bond yields edged down 2.5 basis points to 4.896%.

In the foreign exchange markets, the dollar ⁠index, which tracks the U.S. currency's performance against that of six others, rose for the first time this week, ‌having dropped 0.5% overnight.

The euro was down 0.14% at $1.1711, after rising 0.7% the day before, while the Swiss franc, a key safe-haven currency, weakened, leaving the dollar up 0.22% at 0.7916. The yen was a touch stronger at 157.88 per dollar ahead of a Bank of Japan policy meeting on Friday. No rate hike is expected this time though policymakers could signal ‌an increase may be coming ⁠as soon as April.

Oil prices fell as pressure from geopolitical tensions and an expected build-up in U.S. crude inventories outweighed a temporary halt in output at two large fields in Kazakhstan. Brent ⁠crude futures were down 1.45% at $63.96 a barrel.

(Additional reporting by Stella Qiu in Sydney; Editing by Shri Navaratnam and Elaine Hardcastle)