NEW YORK ( TheStreet ) -- Delek US Holdings (NYSE: DK ) has been downgraded by TheStreet Ratings from buy to hold. The company's strengths can be seen in multiple areas, such as its robust revenue growth, solid stock price performance and compelling growth in net income. However, as a counter to these strengths, we also find weaknesses including weak operating cash flow and poor profit margins. Highlights from the ratings report include: Delek US Holdings, Inc. engages in refining, wholesaling, and marketing petroleum products in the United States. The company operates through three segments: Refining, Marketing, and Retail. Delek US has a market cap of $755.5 million and is part of the basic materials sector and energy industry. Shares are up 89.1% year to date as of the close of trading on Monday. You can view the full Delek US Ratings Report or get investment ideas from our investment research center. null