NEW YORK ( TheStreet) -- PDF Solutions (Nasdaq: PDFS) has been upgraded by TheStreet Ratings from sell to hold. The company's strengths can be seen in multiple areas, such as its impressive record of earnings per share growth, compelling growth in net income and revenue growth. However, as a counter to these strengths, we find that the company's return on equity has been disappointing. PDF Solutions, Inc. provides infrastructure technologies and services for the design and manufacture of integrated circuits(IC) in Asia, the United States, and Europe. PDF has a market cap of $166.7 million and is part of the technology sector and computer software & services industry. Shares are up 32.8% year to date as of the close of trading on Friday.