After oil drop, buy retailers like Amazon in August

Boxes move along a conveyor belt at an Amazon fulfillment center in Tracy, California.
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The price of crude oil collapsed 21 percent in July, setting up a potential winning trade ahead for retail stocks, if history is any guide.

In the past decade, there has been only one other instance when oil prices fell by more than 20 percent over a one-month period. That was in October 2008, when oil lost 33 percent of its value at the heart of the financial crisis.

Market watchers believe the unusual drop in oil prices this month could provide a boost to consumer spending as drivers pay less at the pump.

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Based on estimates from Deltec International Group, a wealth management firm, the severe drop in crude prices, which are now down 52 percent in the past year, will lead to a 1 to 2 percent increase in real incomes.