North American markets started the week higher but again dropped at the end of the day, this time pushed deeper on renewed trade threats against China from U.S. President Donald Trump.

Early trading was a reflex reaction as investors bought into last week’s weakness, said Craig Fehr, Canadian markets strategist for Edward Jones.

The S&P/TSX composite index gained 131 points early, but then closed down 166.51 points or more than 1% to 14,721.75. That’s the lowest level since July 8, 2016.

“I think it’s a reflection of the lack of conviction that we have in the market right now,” Fehr said in an interview.

“I think investors by and large have been a little shell-shocked by the volatility of recent weeks.”

Fehr said the fundamental backdrop for the market, including improved corporate earnings, the economy and interest rates, remain positive. But market swings have sapped the conviction of the bull market.

“So I think we’re probably due for more swings like this, kind of intraday swings and daily swings that are reflective of low conviction at the moment.”

All sectors on the TSX lost ground on Monday, led by cannabis-heavy health care which was down more than 10%. Aphria Inc. closed down 17.35%, Canopy Growth Corp. 14.12% and Aurora Cannabis 16.10%.

Since Canada legalized recreational marijuana use Oct. 17, pot stocks have lost up to about 45% of their value.

The energy sector closed off more than three cent as the price of crude oil continued to fall as investors remained concerned about slowing global demand led by weakness in China.

The December crude contract was down 55¢ at US$67.04 per barrel and the December natural gas contract was down 2.7¢ at US$3.20 per mmBTU.

In New York, the Dow Jones industrial average was down 245.39 to 24,442.92. The S&P 500 index was off 17.44 points to 2,641.25, while the Nasdaq composite lost 116.92 points to 7,050.29.

U.S. markets sustained sharp losses late in the day on reports that Trump is planning new tariffs on all remaining imports from China if the two sides don’t make progress in trade talks next month.

But Fehr said the day’s losses can’t be totally blamed on Trump.

“Certainly concerns about protectionism, global trade and the impact that is going to have on global growth have been a source of concern and risk for this market. And today’s no different.”

He said there’s no guarantee against further market losses, but long-term investors will see this period as a buying opportunity.

The Canadian dollar traded at an average of US76.23¢, its lowest level in nearly seven weeks, and compared with an average of US76.29¢ on Friday.

The December gold contract was down US$8.20 at US$1,233.10 an ounce and the December copper contract was essentially flat at US$2.74 a pound.