A roundup of tech analyst ratings changes: 1) Baidu (BIDU +4.7%) has been upgraded to Neutral by Citi following the 91 Wireless deal. 2) Sonus (SONS +4.7%) has been upgraded to Buy by Lazard. 3) Stamps.com (STMP -7.7%) has been cut to Neutral by B. Riley. 4) Move (MOVE +2.9%) has been started at Overweight by Stephens. 5) Cavium (CAVM -2%) has been started at Reduce by Nomura. 6) Perfect World (PWRD +1.8%) has been upgraded to Buy by Citi. 7) Trina (TSL -0.5%) has been cut to Underperform by Raymond James; shares would be faring worse if not for ReneSola's guidance hike.