A roundup of tech analyst ratings changes: 1) Pac Crest has started coverage on Yelp (YELP +2.9%) with an Outperform. 2) Wunderlich has started coverage on Groupon (GRPN +2.8%) with a Buy. 3) Barclays has upgraded Seagate (STX +0.4%) to Equalweight. 4) Morgan Stanley has launched coverage on Avago (AVGO +1.6%) with an Overweight. 5) Argus has downgraded Accenture (ACN -0.1%) to Hold (previous). 6) LightintheBox (LITB +0.5%) has been started at Outperform by Oppenheimer and Pac Crest, and at Hold by Stifel (underwriter coverage day).