Breaches have a different impact: security, reputational and economical, in that order.

Firstly the security of the breached company is compromised, the company has to identify the source of the breach, fix the issue, etc. Then there is a reputational impact when the data breach is made public. Finally, the economic impact is very difficult to measure it depends on different things, the company size, the information that was compromised, the number of exposed records, the freshness, etc

From my experience, it can vary from few millions up to hundreds of millions just like what happened with the Yahoo Breach (

Moral: It is cheaper invest in cybersecurity before a data breach happen