Peel Hunt has upgraded its rating for Aberdeen Asset Management from hold to buy following this morning's well-received pre-close trading update."Aberdeen's AuM has risen sharply over the last two months, benefiting from the recovery in equity markets. Demand remains high for the group's products and revenue/operating margins are being pushed higher," said Peel Hunt analyst Stuart Duncan.Peel Hunt downgraded Aberdeen previously thinking that most of the good news in the short-term was largely reflected in the share price. However, with the shares having now drifted back, the broker now sees a 12% upside to its unchanged target price of 280p and has therefore raised its rating.Jefferies has reiterated its buy recommendation and 485p target price for seals and cylinders maker Diploma after an upbeat interim pre-close trading update this morning.The broker says that the margin is the source of upside for Diploma: "With the Seals division producing gross margins in the 50-60% range we anticipate that group operating margin has improved from 19.6% to 20.0%. This is a significant improvement on the flat position the company had guided and is a record high."Prime Markets recommends to buy shares of budget airline easyJet, saying that today's first-half guidance upgrade provides 'great upside momentum'."Prime Markets have long viewed Easyjet as the great British success story of the airline industry, with a business model that is both relevant and scalable for the global economic environment today and in the future," said head of dealing Richard Curr.It says that the shares should comfortably hit and exceed new 52-week highs at or above the 500p 'benchmark' last seen in Spring 2010.BC