An after-hours Nasdaq glitch that saw various US technology stocks misquoted resulted in disruption across the world, forcing Asian brokers to cancel deals.
In all, around a dozen share prices were impacted by the glitch, including the stock of Nasdaq itself.
Zynga "rises" 3,000%
Certain third-party data vendors are reported to have mistaken test data for actual prices, resulting in flawed pricing being disseminated by data providers such as Thomson Reuters, Bloomberg and Google Finance. This was despite Nasdaq´s own pricing on its website being unaffected.
The glitch caused howlers such as Amazon appearing to lose $398bn in market cap, while shares in video game developer Zynga were shown to have soared by over 3,000%.
Although the US market was closed at the time of the error, traders in Hong Kong were reported to have had to cancel deals as a result of the glitch.
In a statement, Nasdaq said it was investigating the “improper use” of test data by third parties with a view to ironing out the issues.
In common with the New York Stock Exchange, Nasdaq sends out test data at the end of the trading day as a matter of routine, normally without incident.
With global trading in shares increasingly dependent on electronic trading systems, the potential for mayhem from technical glitches appears to have substantially increased.
The latest incident is by far the first to disrupt market pricing and trades. In August 2013, Nasdaq was forced to halt trading on its exchange for around three hours.
Again, last year the New York Stock Exchange saw around 200 stocks impacted by technical glitches for a similar proportion of the trading day.
There are also instances where “flash crashes” have been widely blamed on technical problems, such as the memorable price action that impacted US stocks during one trading session in 2010.