The energy sector of the S&P 500 has given back nearly all the gains it made last year, when it rose 24% as oil prices rebounded from multiyear lows. Shares of energy companies are on track for their biggest monthly decline since the end of 2015, showing that stabilizing earnings aren’t enough to attract investors. Energy companies in the S&P 500 are off 17% so far this year, making it the index’s worst-performing sector . August has been particularly painful, with energy shares shedding 5.7% through Friday. Volatile trading in oil and gas markets was expected Monday as investors assess the impact of Tropical Storm Harvey, which pummeled Texas over the weekend. The sector has given back nearly all the gains it made last year, when it rose 24% as oil prices rebounded from multiyear lows. The rally in energy companies reflected expectations that oil would continue to rise, […]