Shares of Warren Buffett's Berkshire Hathaway fell just over six percent today to a 20-month closing low of $105,126.
It's also a new intraday low for the stock, which had fallen to $105,300 on October 10 before ending that session at $113,100.
Berkshire hasn't closed below $100,000 in just over two years.
The stock has moved in an enormous range in the last few weeks, closing as high as $147,000 on September 19. That was just over one percent below its all-time high set in December. Tonight, Berkshire is down 28.5 percent from that peak.