I think the one thing that's going on here is that people are saying, uh-oh, the Chinese economy might be slowing more than we thought and the government is having a hard time stimulating it again.

At some point, people may decide that the U.S. stock market has fallen enough. After all, the U.S. economy seems to be getting better, that what happens in China is not going to have that devastating effect on car sales here or how many people buy Apple phones or what happens at - how many people shop at Wal-Mart.

The only reason you would want your currency to fall, if you could control it, is in order to get more exports.

I think it was seen as a symptom that the Chinese leadership may be really scared about their economy.Why would you want to depend more on exports if you're a country that has a stated policy of relying less on exports and more on consumer spending, domestic spending?

I think what the Fed fears is that, if Donald Trump gets big tax cuts and big spending increases that take effect right now, when the economy is close to full employment, they will have to raise rates more rapidly.

There is also a concern that there is a lack of demand of oil. And so when commodity prices fall, it's good if you happen to be a consumer, but it's sometimes seen as symptom of a weakening economy.

China's stock market is not very big. And yet when stock market has a bad day in China, it seems, Europe has a bad day and then we have a bad day.