Vodafone's share price surged on Tuesday on the back of its interim results, though Brewin Dolphin said that it didn't expect such a positive reaction to a "broadly in-line" report from the telecoms giant.The broker said that Tuesday's market reaction - shares up 6% by early afternoon at 220.25p - "is a surprise to us and indicates that investors were more sceptical going into the results (it also confirms the importance of the organic revenue number for investors)". Similarly, Richard Hunter, head of equities at Hargreaves Lansdown Stockbrokers said Vodafone "has posted a relatively comforting set of numbers" despite persistent challenges.JPMorgan Cazenove has lifted its rating for Betfair from 'neutral' to 'overweight' on the back of the online betting group's top-line momentum, marketing firepower and product innovation. It is the bank's top pick in the gambling sector."Over the past two years, Betfair chief executive Breon Corcoran has led a major product overhaul. In our view, Betfair now ranks among the best-quality operators in the UK market and is leading the way in sportsbetting innovation," the bank said in a research report.An extremely brief trading update from Renishaw was well-received by the market on Tuesday, though broker N+1 Singer has maintained a neutral stance on the engineering stock due to a cautious outlook for next year."While underlying demand is very positive, we believe the main driver of outperformance is irregular orders, which we would not expect to recur in [the fiscal year ending June 2016]."