Some of the most active companies traded Friday on the Toronto Stock Exchange:Toronto Stock Exchange (16,039.26, down 42.83 points)Aurora Cannabis Inc. (TSX:ACB). Healthcare. Up 60 cents, or 14.85 per cent, to $4.64 on 39.02 million shares.Canopy Growth Corp. (TSX:WEED). Healthcare. Up 63 cents, or 3.26 per cent, to $19.98 on 9.3 million shares.Aimia Inc. (TSX:AIM). Loyalty programs. Up 41 cents, or 14.64 per cent, to $3.21 on 6.04 million shares.Cenovus Energy Inc. (TSX:CVE). Oil and gas. Down 16 cents, 1.11 per cent, to $14.28 on 5.4 million shares.Obsidian Energy Ltd. (TSX:OBE). Oil and gas. Up two cents, 1.32 per cent, to $1.53 on 3.9 million shares.NexGen Energy Ltd. (TSX:NXE). Miner. Down 11 cents, or 3.62 per cent, to $2.93 on 3.8 million shares.Companies reporting major news:Canadian Natural Resources Ltd. (TSX:CNQ). Oil and gas. Up 11 cents, or 0.24 per cent, to $46.30 on 1.9 million shares. The company is considering adding a 30,000- to 40,000-barrel-per-day bitumen-only project to its Horizon oilsands mine to take advantage of excess ore production and pipeline capacity. The proposed project could be approved as early as 2019 and would continue a trend in the sector to bolt on brownfield production to avoid the high costs and risks of building new mines from scratch.Hydro One Ltd. (TSX:H). Utilities. Down 27 cents, or 1.17 per cent, to $22.71 on 444,246 shares. Ontario’s largest electricity distributor says its third-quarter profit was down six per cent from last year as a result of costs associated with the proposed $6.7-billion acquisition of Avista Corp., a U.S. utility company based in Spokane, Wash. Profit attributable to common shareholders was $219 million (37 cents per share), down from $233 million (40 cents per share) last year. Excluding the costs associated with Avista, Hydro One’s adjusted profit was up two per cent at $237 million.