Japan's Nikkei [.T] and China's main bourses [.SS] tumbled again overnight as trade concerns persisted, and Europe's STOXX 600 index <.STOXX> hit a 22-month low as U.S. markets prepared to re-open after their worst week since March. [.N]
The lack of confidence continued to boost traditional safe haven assets. The yen and Swiss franc both made ground on a subdued dollar in the currency markets [FRX/] while gold hit its highest since the end of July. [GOL/]
Germany's government bonds also rallied and the euro climbed as high as $1.16 despite a humbling regional election result for Chancellor Angela Merkel's conservative Bavarian allies on Sunday.
"I don't think there is really any appetite to dive back in (to stocks), and the Saudi situation is just another ball for investors to have to juggle," said CMC Markets' senior analyst Michael Hewson.
"If the trend we saw last week continues, it is going to be very hard for Europe to rally... The outlook remains very uncertain," Hewson added.
The Saudi situation remained front and centre after Riyadh appeared to retaliate to U.S. President Donald Trump's promise of "severe punishment" if it turns out that prominent Saudi dissident Jamal Khashoggi, a U.S. resident and Washington Post columnist, was killed while visiting his country's consulate in Istanbul.
The official Saudi Press Agency (SPA) quoted an unnamed official on Sunday saying the kingdom "will respond with greater action," if there are measures and that its economy "has an influential and vital role in the global economy."
Traders read that as meaning driving oil prices up further. Brent crude responded by jumping 1 percent [O/R] which in turn saw Saudi stocks <.TASI> recover the full 3.5 percent they had lost on Sunday when the diplomatic tensions flared.
Turkey's lira <TRYTOM=D4> was another big riser on Monday, jumping 1.5 percent to its highest since mid-August after Trump cheered the release of a U.S. pastor who had been under house arrest in Turkey.
Investors hope his release can lead to an improvement in strained U.S.-Turkey relations.
"The lira is likely to benefit at least modestly during the period between now and the CBT (central bank) meeting of 25 October where we anticipate the next 300 bps rate hike," ING analysts wrote in a note.
But the broader global picture was still cautious.
Wall Street futures remained red albeit only just [.N], while Saudi Arabia's riyal currency was still testing the boundaries of its peg at 3.7514 to the dollar - its weakest spot rate since June 2017.
The Saudi central bank maintains a peg of 3.75 riyals to the dollar, and usually the currency fluctuates in a range of about 3.7498-3.7503.
Overnight, MSCI's broadest index of Asia-Pacific shares outside Japan <.MIAPJ0000PUS> had fallen 1 percent as Shanghai <.SSEC> ended down 1.5 percent and just off a four-year low. [.SS]
Japan's Nikkei <.N225> slumped 1.8 percent on Monday, with carmaker shares <.ITEQP.T> hitting 13-month lows after Washington said it would seek a provision about currency manipulation in future trade deals with Japan.
MSCI's broadest gauge of the world's 47 top stock markets <.MIWD00000PUS> was off 0.2 percent after a sizeable 3.87 percent decline last week - its biggest since March - to a one-year nadir.
Over the weekend, China central bank governor Yi Gang said he still saw plenty of room for adjustment in interest rates and the reserve requirement ratio (RRR), as downside risks from trade tensions with the United States remain significant.
In London, sterling recovered from renewed Brexit deal worries, while commodities trading remained hung up on the Saudi tensions and the risk they could drive up prices.
Saudi Energy Minister Khalid al-Falih had said on a trip to India that his country is planning to push up production, but the prospect of a major diplomatic feud with the West trumped that sentiment.
Investors suspect the developments could ultimately undermine the leadership of Crown Prince Mohammed bin Salman if they escalate and destabilise the oil-rich kingdom.
Brent crude futures were last up 1 percent to $81.26 per barrel, bouncing back from Friday's near-three-week low of $79.23.
"People had thought the Saudis would make up for the fall in Iran's output. If they are starting to use oil as their weapon, that will be a whole new chapter," said Kazuhiko Fuji, senior fellow at Research Institute of Economy, Trade and Industry, a think-tank affiliated with the Japanese government.
(Reporting by Marc Jones; Additional reporting by Hideyuki Sano in Tokyo; Editing by Gareth Jones and Hugh Lawson)
By Marc Jones