The 11 companies, spanning industries from mining and pharma to technology, have market values of more than $160 million and are trading under $4. Based on analysts' buy and hold ratings, strong company fundamentals and industry outlook, these stocks could present an attractive buying opportunity. The stocks are stacked based on their upside, from great to greatest. 11. Sirius XM Radio ( SIRI) operates two satellite radio systems offering music, sports, entertainment and news on a subscription basis. Available in vehicles, radios, smartphones and on the Internet, subscribers can chose from a variety of package starting under $20. Sirius' first-quarter revenue rose 9% to $723.8 million from a year earlier. Net income increased to $78 million from $42 million. At the end of the quarter, the company's cash and cash equivalents stood at $433.7 million, up 62%. New subscriptions totaled 373,000, bringing the total to 20.6 million. The company reaffirmed its 2011 guidance with revenue estimated at $3 billion and adjusted EBITDA at $715 million. Meanwhile, Sirius raised free cash flow estimates to $350 million from $300 million. With regard to subscribers, the company forecasts a net addition of 1.4 million this year. Of 13 analysts covering the stock, 46% give it a buy, while 46% rate it hold. On May 8, analysts at Maxim Group assigned a buy rating to the stock and raised its price target to $2.5 from $2.2 a week earlier. This indicates a 6.4% potential upside from current levels.