More than 257 million individuals were affected by security breaches over the past three years, according to a new report. 

The report examined large scale breaches such as the Equifax breach of 2017, Marriot breach of 2018 and the Yahoo breach of 2016, 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 include: 

• 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.