NEW YORK (TheStreet) -- Bank of America (BAC) - Get Report stock is climbing 2.22% to $13.83 in afternoon trading on Friday, following an upgrade to "buy" from "sell" by CLSA analyst Mike Mayo.

Mayo raised his price target on the stock to $16 from $15.

The bank's low valuation could prompt an event such as a restructuring or spinoff to improve its "lousy efficiency," Mayo told Bloomberg. 

Bank of America's efficiency ratio, or how much it costs to generate a dollar of revenue, is the worst of the biggest U.S. banks in the high 60% range, according to Mayo.

Bank of America shares have tumbled nearly 20% so far this year, granting investors a margin of safety, Mayo said in a noteThe company's parts are worth 40% more than its current market capitalization. 

TheStreet Recommends

"While an activist is an outside shot, increased shareholder pressure seems likely," Mayo wrote, Bloomberg adds. He urged the bank to demonstrate economies of scale, restructure, sell assets or break up.

Separately, TheStreet Ratings team rates the stock as a "buy" with a ratings score of B-.

Bank of America's strengths such as its revenue growth, growth in earnings per share, increase in net income, attractive valuation levels and expanding profit margins outweigh the fact that the company has had lackluster performance in the stock itself.

You can view the full analysis from the report here: BAC

TheStreet Ratings objectively rated this stock according to its "risk-adjusted" total return prospect over a 12-month investment horizon. Not based on the news in any given day, the rating may differ from Jim Cramer's view or that of this article's author.