Pedestrians walk by a Verizon Wireless store on January 22, 2015 in San Francisco, California.

Goldman Sachs upgraded Verizon and Charter Communications to buy from neutral, believing the broadband providers have been unfairly punished as other telecommunications giants pursue costly acquisitions.

"We believe that broad underperformance across the sector has been driven by a few key factors, including concerns about fundamental headwinds, M&A uncertainty and rising interest rates," the Goldman note stated. "At a higher level, we believe the pursuit of vertically integrated business models (via levered M&A) by some operators has caused investors to question whether large cap stocks in the telecom and cable sector can outperform while the industry is undergoing such significant transformation."