UK markets closed

London Stock Exchange denies it was hit by cyber attack

Oscar Williams-Grut
Senior City Correspondent, Yahoo Finance UK
Financial market figures are shown on big screens and a ticker at London Stock Exchange. Photo: Chris J Ratcliffe/Getty Images

Authorities have denied the London Stock Exchange (LSE.L) was a victim of a cyber attack last summer, after the Wall Street Journal reported UK cyber security officials were investigating.

The opening of the London Stock Exchange was delayed by over an hour and a half in August 2019 as a result of what the operator said was “a technical software issue”.

The Wall Street Journal reported over the weekend that UK government agencies were investigating whether the outage could have actually been caused by a cyber attack, aimed at disrupting a piece of critical UK infrastructure. The report was based on unnamed sources close to the investigation.

However, cyber security agencies and the stock exchange operator both downplayed fears and said there was no cyber attack.

READ MORE: London Stock Exchange delayed by 'technical issues'

“The incident was caused by a technical software configuration issue following an upgrade of functionality and was not a cybersecurity incident,” a spokesperson for the London Stock Exchange group told Yahoo Finance UK.

A spokesperson for the National Cyber Security Centre (NCSC), a division of GCHQ, told Yahoo Finance UK: “The NCSC has not treated the LSE outage as a cyber security related incident and has not investigated it as such.”

The NCSC is understood to have been in touch with the London Stock Exchange after the outage. However, this is relatively routine. The NCSC is a government agency tasked with ensuring the digital security of the state and critical national infrastructure, including key parts of the financial system. The NCSC monitors goings on at the London Stock Exchange as a result.

The Treasury did not immediately respond to a request for comment.

A spokesperson for the London Stock Exchange Group said it “takes its commitment to run orderly markets for its members seriously and has thoroughly investigated the root cause of the issue to mitigate against any future incidents.”

While rare, delays to stock market openings are not unheard of and happen around the world. The London Stock Exchange was struck by a similar issue in 2018.

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