Mark Glassman, Smartmoney
In Asia, the floor collapsed on the Thai stock market Tuesday, pulling other Eastern markets down along with it. The third-largest Asian market lost 13% of its value, the equivalent about $20 billion on Tuesday, prompting officials to close trading for a half hour. As the dust cleared, the country's central bank took action, removing barriers to foreign investment set up a day earlier to curb speculative buying of the Thai currency.
It should be added that at "third-largest," it's waaaaay smaller than even the Nikkei, which is in turn much smaller than the American market. Still, the fact that modest controls to stabilize currency flows should cause a market drop of that size give a sense for how frothy some of the financial action is.