NYSE, SEC Seek Causes for Wild Stock Gyrations at Market Open

The New York Stock Exchange is probing what caused wild price swings and trading halts when the market opened on Tuesday as shares for dozens of the biggest US companies suddenly plunged or spiked.

A “technical issue” that the exchange didn’t immediately identify resulted in some gyrations that spanned almost 25 percentage points between the high and low in a matter of minutes. Banks, retailers and industrial companies were among those affected, including Wells Fargo & Co., McDonald’s Corp., Walmart Inc. and Morgan Stanley.

Watch: The NYSE is investigating wild price swings from the open on Tuesday.

Source: Bloomberg

The freakish action bears hallmarks of past episodes in which computer malfunctions led ...