TSC Ratings provides exclusive stock, ETF and mutual fund ratings and commentary based on award-winning, proprietary tools. Its "safety first" approach to investing aims to reduce risk while seeking solid outperformance on a total return basis.The following ratings changes were generated on Wednesday, April 29. We've upgraded retail store chain operator Bed Bath & Beyond ( BBY) from hold to buy, driven by its largely solid financial position with reasonable debt levels by most measures, good cash flow from operations, expanding profit margins, attractive valuation levels and notable return on equity. We eel these strengths outweigh the fact that the company has had somewhat weak growth in earnings per share. Bed Bath & Beyond has a quick ratio of 0.7. Net operating cash flow increased 27.3% compared with the same quarter last year, to $476.9 million. The company's gross profit maring is 40.8%, which has decreased from the same period last year. The 7.4% net profit margin outperformed the industry average. Revenue fell 0.5% from the year-ago quarter, and EPS are also down. We've upgraded Dionex ( DNEX) from hold to buy, driven by its revenue growth, largely solid financial position with reasonable debt levels by most measures, notable return on equity, impressive record of earnings per share growth and increase in net income. Although no company is perfect, currently we do not see any significant weaknesses which are likely to detract from the generally positive outlook. Revenue increased by 5.1% since the year-ago quarter, and EPS are up 20.8%. We feel that the company's two-year trend of EPS growth should continue. Dionex's debt-to-equity ratio of 0.1 is below the industry average, and it maintains a quick ratio of 1.5. Return on equity has improved slightly compared with the year-ago quarter. Net income is up 14.8%, from $14.8 million to $17 million.