In recent months, billionaire investors Warren Buffett and Carlos Slim have been making bold moves in the energy sector ($SREN), signaling a strong resurgence of interest. Legendary investor Warren Buffett’s holding company Berkshire Hathaway (BRK.A) (BRK.B) poured another $434.8 million into Occidental Petroleum Corporation (OXY) through June 17, further solidifying its already huge position in the stock. Similarly, Carlos Slim’s investment company, Control Empresarial de Capitales, injected $75.5 million into PBF Energy Inc. (PBF) this month, marking a significant vote of confidence in the s…