The midday calm in financial markets has broken

Markets were eerily calm midway through trading today but we're entering the final hour of equity trading now and there is some fresh pressure.

The S&P 500 is down 163 points, or 3% to 5182 after rising as high as 2520 in the midday bounce.

I'm keeping an eye on bitcoin as a barometer on sentiment as well and it's back into the low $53,000s.

So far the moves haven't spread to bonds or FX but there certainly could be fireworks.