A sharp rise in the share price of Admiral recently has prompted broker Credit Suisse to downgrade its rating on the car insurer to 'neutral' from 'outperform.'The stock has rallied from 855p at end of June to 1,012p, Credit Suisse notes. This leaves just 8.5% upside to its unchanged target price of 1,097p, which compares with a sector average of 18%, it says.