Take a look at the page below — everything is dropping.

I know the stories — QE was priced in, Ireland and Greece, Chinese tightening. I just can’t get them to crystallise into a coherent account of these moves across such a range of markets. Could it just be that uncertainty is leading to profit-taking on a big scale?
How about this: it’s all about China. Chinese demand is driving the uptrends in commodities from copper to wheat, and China buys US Treasuries to keep its currency fixed, so if China is tightening monetary policy and allowing its currency to appreciate, these markets should fall. The USD is rising as leveraged players unwind carry trades in commodity-producing countries and return USD to the US (so the USD can be rising even as US financial assets fall). The equity market knows that China is an important source of growth at a time when the developed world is recovering from a financial crisis (and the S&P 500 is an international index). There is additional pressure on the EUR because of the ongoing and rather fuzzy crisis in the Eurozone (What is the crisis? Is it the Irish banks, or the sovereign, or the risks to Portugal, or the new resolution regime, or a bit of everything?), and from the fact that all these assets had run a long way in the other direction in expectation of QE, which will feed into asset prices but not necessarily smoothly.
So how real is this Chinese tightening story? It takes a lot to kill a leveraged boom.