The largest breaches over the past three years have caused massive and irreparable damage

Publicly traded companies suffering the worst data breaches averaged a 7.5 percent decrease in stock price, a Bitglass report reveals.

Bitglass researched the three largest data breaches of publicly traded companies from each of the last three years in order to uncover cybersecurity trends and demonstrate the extensive damage that can be done by improper security. Among the incidents detailed in the Kings of the Monster Breaches report are the Marriott breach of 2018, the Equifax breach of 2017 and the Yahoo! breach of 2016.

The report explores the causes, repercussions and company responses for each of these preeminent breaches. Additionally, it recaps three of the most significant cybersecurity incidents that affected government agencies and private companies over the last three years.

The report’s findings highlight the similarities between leading breaches and suggest that organizations have not been learning from the mistakes of their peers.

Key findings:

• The mean number of individuals directly affected by each breach was 257 million.
• To date, these breaches have cost their companies an average of $347 million in legal fees, penalties, remediation costs and other expenses.
• The average post-breach market cap decrease was $742 million (this excludes the outlier Facebook breach which lost $43 billion in market cap).
• It took an average of 46 days for the companies’ stock prices to return to their pre-breach levels – Equifax’s stock price still has yet to recover.

“The largest breaches over the past three years have caused massive and irreparable damage to large enterprises and their stakeholders around the globe,” said Rich Campagna, Chief Marketing Officer of Bitglass.

“This should serve as a stark warning to organizations everywhere. If massive companies with seemingly endless resources are falling victim to external attacks, then companies of all sizes must remain vigilant in their cybersecurity efforts. It is only by taking a proactive approach to security that breaches can be prevented and data can truly be kept safe.”