'Head fake' rallies are common during bear markets and this could be one

Pedestrians pass in front of the New York Stock Exchange, May 24, 2019.
Michael Nagle | Bloomberg | Getty Images

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The biggest three-day rally for the Dow in almost 90 years is giving investors hope that this bear market has bottomed, but Barclays noted a bounce like this is usually not sustainable while crawling out of the depths of a sharp rout.