A bet on oil is a bet on the US and global economy, middle east politics on shale oil production trends and on solar prices. Is the economy going to expand or contract with impacts on demand? Will Trump sanction Iran? Will shale oil production continue to increase and depress prices or flatten out? Is solar going to continue crashing in price or flatten? If can forecast all these, you can forecast oil price and company stocks. Good luck!
PS I bought BP and PBR at lows after scandals and have been happy despite three year crash in oil prices.