The number of new COVID-19 cases in the U.S. and elsewhere is shaking investors' optimism about a speedy economic recovery.

An uptick in U.S. cases and a bleak economic forecast from the U.S. Federal Reserve are sending stocks plunging.

Calfrac Well Services Ltd. says it is seeking advice on changes to its capital structure but doesn't know of any "material change'' that would account for a 75.6 per cent increase in its share price on Tuesday.

The Canadian dollar traded for 72.53 cents US compared with 72.65 cents US on Thursday.

The S&P/TSX composite index closed up 132.87 points at 14,966.56.

North American stock markets had one of their best performances in years last month.

Canada's benchmark stock index inched higher thanks as oil prices moved up.

In Toronto, however, Canada's benchmark index was up in early trading.

Concern about economic damage from the virus has dampened a brief bout of investor optimism.

Washington has already approved a $2-trillion financial aid package, but investors are hoping for more.