A technical error on the New York Stock Exchange on Monday morning trading caused wrong stock prices and volatility halts across several equities, most notably causing a huge 99.9% drop in the price of Warren Buffett’s famous Berkshire Hathaway (NYSE:BRK-A) A-shares.

While Berkshire Hathaway’s B-shares (NYSE:BRK-B), which trade at 1/1,500th the price of the A-shares, had a drop of up to 1.1% on Monday, they seemed to be mostly unaffected by the error. However, both A and B shares showed strong volatility as A-shares started trading again around 11:35 a.m. Eastern Time.

According to a statement from the NYSE, the technical error came from price bands for the whole industry published by the CTA SIP, causing halts in trading for many stocks listed on the NYSE Group exchanges. The affected stocks have since reopened or are being reopened, with the error fixed.

Price bands are put in place to reduce too much volatility or extreme changes in individual stock prices. Despite the interruption, the NYSE reassured investors that affected stocks are going back to normal trading conditions.

Chipotle (NYSE:CMG) stock was temporarily halted due to volatility about 14 minutes after the market opened, even though it had only a small 1.2% drop. Also, trading halts were seen for Horace Mann Educators (NYSE:HMN) and Franco-Nevada Corp (NYSE:FNV), a company that specializes in royalty and streaming focused on gold.

Monday’s technical error follows closely after another incident involving the temporary disappearance of live calculations for the S&P 500 (^GSPC) and Dow Jones Industrial Average (^DJI) for about an hour.

Just a week before, the NYSE made a change to settle stocks within one business day to comply with a new rule from the Securities and Exchange Commission. This adjustment shortened the time between trade and settlement from two days to one, aiming to make market operations more efficient.