Energy
Although energy can be harvested from myriad sources – coal, nuclear, hydroelectric, wind, solar – nothing can come close to challenging the dominance of oil and gas as a source of energy.
The profitability of the energy sector is highly dependent on commodity prices. Commodity prices are cyclical, as are the sector's profits. It's better to buy when prices are at a cyclical low than when they're high and hitting the headlines.
Keep an eye on reserves and reserve growth because these are the hard assets the company will mine for future revenue.
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