Analysts at Auriga upgraded Hewlett-Packard Company (NYSE:

) from “hold” to “buy.” HPQ's shares closed at $23.60 on Friday. Hewlett-Packard's PEG ratio is 0.70. Analysts at Credit Suisse upgraded SLM Corporation (NYSE:

) from “neutral” to “outperform.” SLM's shares closed at $12.73 on Friday. SLM's trailing-twelve-month operating margin is 53.10%. Analysts at Citigroup upgraded Public Service Enterprise Group Inc (NYSE:

) from “hold” to “buy.” PEG's shares closed at $31.62 on Friday. PEG's trailing-twelve-month revenue is $11.68 billion. Piper Jaffray upgraded Yingli Green Energy Holding Co Ltd (NYSE:

) from “neutral” to “overweight.” YGE's shares closed at $5.26 on Friday. Yingli Green Energy's PEG ratio is 0.41.