Canada’s main stock index began the week higher as Alberta production cuts helped to lift oil prices to their largest gain since June, while investors felt relief from a preliminary trade truce between the U.S. and China.

The January crude contract gained 4% cent or US$2.02 to US$52.95 per barrel.

Western Canadian Select rose 9.6% or US$1.48 to US$16.93 after Alberta Premier Rachel Notley instructed the province’s energy regulator to direct oil producers to cut production by 8.7% starting Jan. 1.

Oil prices also rose on continued expectation that OPEC on Thursday will cut production by up to 1.5 million barrels a day to support prices.

“I think those two factors combined are providing a little bit of lift for oil prices,” said Craig Fehr, Canadian markets strategist for Edward Jones.

The S&P/TSX composite index reached its highest level in nearly a month, closing up 77.16 points to 15,274.98.

The energy sector gained almost 4% cent and higher gold prices helped the materials sector to rise more than 2%.

The February gold contract was up US$13.60 at US$1,239.60 an ounce and the March copper contract was up US2.2¢ at US$2.81 a pound.

Health care fell 1.8% as shares of cannabis producer Aphria Inc. plunged nearly 28% after short-sellers called the Canadian company a “black hole” and alleged that its recent international acquisitions totalling $280-million were “largely worthless.”

The Canadian dollar traded at an average of US75.81¢ compared with an average of US75.18¢ on Friday. That’s the biggest daily gain since Oct. 1.

The January natural gas contract was down US27.3¢ at US$4.34 per mmBTU.

In New York, the Dow Jones industrial average was up 287.97 points at 25,826.43. The S&P 500 index gained 30.20 points at 2,790.37, while the Nasdaq composite was up 110.98 points at 7,441.51.

A weekend 90-day ceasefire between the U.S. and China on imposing higher tariffs was a catalyst for global markets to rise even though a final resolution is far from certain, Fehr said in an interview.

“It is far too early to sound the all-clear signal when it comes to the trade tension that exists between the U.S. and China,” he said.

“That’s an encouraging signal that both sides are willing to come to the table but this is far from a concrete agreement that provides a road map for what trade looks like going forward. It’s premature to suggest that equity markets can unshackle themselves from the trade worries at this point.”