Japan, which has seen an extraordinary rally this year, saw an epic pullback today.

The Nikkei plunged 7.3%. That's the equivalent of 1,117 points in the Dow (it closed at 15,307 yesterday).

This is the biggest sell-off since March 2011, when Japan was hit by a tsunami.

"A short-term reversal has been long overdue," said DoubleLine's Jeff Gundlach in an email this morning.

The sell-off followed warnings from the Federal Reserve that it could begin to taper its monetary stimulus programs within a few months should the economic data warrant it.

A major catalyst for the global sell-off also seems to be the unexpected contraction signal seen in China's manufacturing industry.

Here's what the Nikkei looked like on Thursday via Bloomberg:

For some context, here's the 1-year chart: