Canada's main stock index rose on Wednesday, buoyed by cannabis stocks as investors looked ahead to the prospect of a Democrat-controlled Senate in the United States.

Democrats won one US Senate race in Georgia and led in another on Wednesday, moving closer to a sweep in a deep South state that would give them control of Congress and the power to advance President-elect Joe Biden's policy goals.

At 9:36 a.m. ET (14:36 GMT), the Toronto Stock Exchange's S&P/TSX composite index was up 70.73 points, or 0.4%, at 17,753.24.

Healthcare sector jumped 7.8% with cannabis stocks being the biggest gainers.

The energy sector climbed 1.1% as US crude prices were up 0.1% a barrel, while Brent crude added 0.5%.

The financials sector gained 1.0%. The industrials sector rose 0.8%.

The materials sector, which includes precious and base metals miners and fertilizer companies, lost 0.5% as gold futures rose 0.4% to $1,959.9 an ounce.

On the TSX, 137 issues were higher, while 79 issues declined for a 1.73-to-1 ratio favouring gainers, with 19.94 million shares traded.

The largest percentage gainers on the TSX were Canopy Growth Corp, which jumped 14.7% and Aurora Cannabis Inc, which rose 12.4%.

Lightspeed POS Inc fell 4.0%, the most on the TSX, after TD Securities raised target price to C$105 from C$82. The second biggest decliner was Iamgold Corp, down 4.0%.

The most heavily traded shares by volume were Zenabis Global Inc, Toronto-Dominion Bank and Bank of Nova Scotia.

The TSX posted 11 new 52-week highs and no new lows.

Across all Canadian issues there were 45 new 52-week highs and 5 new lows, with total volume of 43.47 million shares.