This is according to the Wall Street Journal as of 9:59 PM BST, which I think was just before 4 PM this afternoon in the eastern US, just over an hour ago. Brent is the main international price, which has been several dollars above the main US price, West Texas Intermediate (WTI) for a long time, with WTI having fallen below the $50 per barrel price some weeks ago.
The article pinpoints two signal items in this sharp price decline today. The first is that US oil production is at record levels. The other is on the demand side, with slowdowns in demand from Brazil and India noted, but the really big item a piece of information released today by the Chinese government, and I quote:
"Chinese manufacturing fell to a two year-low, according to data released Monday [today]."
To those, such as anne over on Economists View, who think that all is just hunky dory in China and that the 7% growth rate reported for the second quarter is credible, well, it is not.
My own private sources say that the Russians think Chinese growth is now more in the 4-5% range, and I note that not only are the Russians currently making lots of deals with, and friendly with, China, but they are also very experienced in the arts of data manipulation that it appears the Chinese are engaging in again.
OTOH, on Econbrowser is a guest post by Jeffrey Frenkel who argues that what burst the Chinese stock bubble in June was a tightening of margin requirements by Chinese regulatory authorities. So, they goosed the bubble up, and since it has fallen they have engaged in extraordinary actions to slow its slide. But they may well have been the parties who triggered the peak and the subsequent decline by their own actions.