Tesla downgraded to 'sell' by Goldman Sachs

Goldman Sachs analyst David Tamberrino says it's time to sell your Tesla stock.

Tamberrino downgraded Tesla's stock to a "sell" rating on Monday morning.

The company's shares dipped nearly 5 percent on Monday. They've dropped by more than 10 percent since the company reported its financial results last week.

The Goldman Sachs analyst said "the acquisition of SolarCity - which is undergoing its own business model transition - comes at a time when we believe Tesla should be singularly focused on becoming a mass automobile manufacturer."

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