Catch up on today's top five analyst upgrades with this list compiled by The Fly: 1. Palo Alto Networks (PANW) upgraded to Buy from Neutral at Cleveland Research with the firm saying it's channel partner checks indicate favorable revenue/billings growth in the low-20% range, versus high teens previously, and the product refresh could be a source of upside with increased hardware growth. 2. Verisk Analytics (VRSK) upgraded to Overweight from Neutral at JPMorgan with analyst Andrew Steinerman saying he believes sustainable high-single-digit organic revenue growth is "back in sight" following last night's "strong" fourth quarter results. 3. Tesaro (TSRO) upgraded to Outperform from In Line at Evercore ISI with analyst Steven Breazzano saying he believes the stocks' valuations are now attractive on a long-term basis following their pullbacks. 4. Clovis (CLVS) was upgraded to Outperform from In Line at Evercore ISI and to Outperform from Sector Perform at RBC Capital. 5. Wolverine World Wide (WWW) upgraded to Buy from Neutral at DA Davidson with analyst Andrew Burns saying the company is positioned for accelerating growth following a multi-year restructuring. This list is just a portion of The Fly's full analyst coverage. To see The Fly's full Street Research coverage, click here.