Every single sector in London was either flat or in the red on Thursday after comments from the Federal Reserve and worse-than-expected data from China prompted a worldwide market sell-off .The Fed last night signalled that it would begin to taper its stimulus programme this year and bring it to a complete halt by next year if the recovery continues to pick up. Meanwhile, gloomy factory-activity figures from China continue to point to a slowdown in the world's second-largest economy.Unsurprisingly, typically 'riskier' stocks such as miners and financials were feeling the heat today as investors sought out safe-haven assets.Shavaz Dhalla, a Financial Trader at Spreadex, said this afternoon that the falls on markets over recent weeks clearly haven't been severe enough to encourage bargain-hunters back in."In fact, the last thing investors are focusing on at the moment is whether they should be taking on any more risk. More than likely, the same investors are probably wondering whether holding equities at the moment, in the context of officials relinquishing stimulus measures, is actually a smart idea."Mining stocks largely bore the brunt of the slump in risk appetite, tracking large declines in commodity prices. Precious metal peers Polymetal, Randgold and Fresnillo were among the worst performing after gold prices dropped as much as 4.8% to $1,286.20 an ounce, its lowest level since September 2010. Rio Tinto and BHP Billiton were also firmly lower.Market volatility also continues to affect Aberdeen Asset Management, another heavy faller today, while high-yielding insurance peers Prudential and Old Mutual dropped as government bond yields across the globe surged.Top performing sectors so far todayBottom performing sectors so far todayTechnology Hardware & Equipment 966.47 -3.93%Financial Services 6,321.71 -3.91%Beverages 13,956.41 -3.64%Industrial Engineering 8,903.68 -3.55%Mining 15,170.46 -3.53%