The disposition effect plays a very important role in explaining this stock momentum.

There's nothing special about a stock price six months or a year ago. Investors want to make sure that the current price is high relative to what they paid for it.

We now have a better idea than ever before about what is driving stock price momentum.

We found that it is a type of psychological bias on the part of many investors that seems to drive momentum. Investors tend to hold on to their losing stocks too long and sell their winners too quickly. This triggers momentum.

With the stock trading at premium multiples and momentum investors exiting the stock, it may take some time ... to re-establish an upward trend.

Despite the economic slowdown around the world, China is still doing relatively well. However, when winter comes, domestic demand in China will slow down and there will be negative movements in the equities market...