Stocks Stumble at Outset Friday Canada''s main stock index opened lower on Friday, weighed by technology and cyclical stocks, while upbeat U.S. job data in May raised concerns about a tighter monetary policy. The SP|TSX let go of 170.48 points, to open the week’s last session at 20,861.33. The Canadian dollar acquired 0.05 cents to 79.59 cents U.S. CIBC raises the rating on Canadian National Railway to outperform from neutral. CN shares dumped 50 cents to $148.17. National Bank of Canada started coverage on Dentalcorp Holdings with an outperform rating. Dentalcorp shares hiked 24 cents, or 2%, to $12.43. CIBC cut the rating on Martinrea International to neutral from outperform. Martinrea shares handed back 37 cents, or 3.7%, to $9.88. Ontario Premier Doug Ford claimed a sweeping election victory in Canada''s most populous province on Thursday, as media projected a second term for his right-leaning Progressive Conservative party with an enhanced majority. ON BAYSTREET The TSX Venture Exchange lopped off 6.07 points to 722.40.