After putting its fair value rating on Hargreaves Lansdown on review last week, Singer Capital Markets decided to upgrade the wealth management firm to buy on Monday, "The recent potential U-turn on payments to platforms and share underperformance has presented a long-awaited buying opportunity in our view. HL's final results demonstrated the continued robustness of the platform and, if it were not for wider equity market weakness, underlying estimates would have been upgraded."The group, which in 2011 celebrated its 30th year since formation, reported last week that revenue rose 31% in the year ended 30 June, while pre-tax profit jumped 46%. The total dividend was raised by 59% on last year at 18.87p. "There remains significant regulatory uncertainty but management have been robust in clarifying the potential impact of the platform proposals and the ability of the business to adapt to protect revenues and profits."The broker has raised its target price to 570p, from 550p.Nevertheless, the stock was not immune to the steep sell-off on Monday, with the shares 1.86% down at 490.2p by 11:44.