Top-ranked analyst: Buy Western Digital

Daniel Acker | Bloomberg | Getty Images

One of the best analysts on Wall Street told clients to buy Western Digital because the shares have an extremely cheap valuation and investors are underestimating the staying power of hard-disk drives.

Hard drives "will not be completely displaced by SSDs (flash memory solid-state drives) over the next decade," Barclays' Mark Moskowitz wrote in a note to clients Wednesday.

Western Digital's "valuation is too low, and multiples can increase longer term," the analyst added.

Moskowitz's picks have a 15 percent one-year average return, according to analyst ranking service TipRanks, placing him in the top 3 percent of all Wall Street analysts covering any industry.