Three beleaguered oil giants Conservative win may give oil patch a lift.

Over the past five years, Canadian energy stocks have been horrible investments, crushed by a huge price differential between U.S. and Canadian crude, and a federal government that seems bent on eliminating fossil fuels. Most who have wagered on a turnaround in the sector have regretted their decision, but a few shrewd traders have profited from relatively short-term moves, buying after the latest disastrous dip, then selling on the slightest hint of good news.  For the energy...