UK stocks plunged on Wednesday amid mounting concerns over instability in Spain. Spanish 10-yer bond yields jumped above 6% after thousands of protestors gathered in Madrid to oppose fresh austerity measures. Pessimistic comments from the Federal Reserve Bank of Philadelphia President, Charles Plosser also send the UK equities lower. Charles Plosser said on Tuesday that QE3 may fail to boost faltering US economy. The FTSE 100 Index sank 1.61% and is currently trading at 5,765.18. All sectors within the index fell. The top-losers were basic materials and technology firms. Anglo American, Antofagasta and BHP Billiton shed 3.89%, 2.08% and 2.76%, respectively. Among technology firms, Sage Group dipped 1.33%. Financials also followed downward trend, with Barclays and HSBC retreating 4.95% and 2.26%.