Markets are closed, but it's down 13% in after-market trading now.
I remember a few commentors on HN recently saying they have made large gains by buying stock of companies after the news of cyber security breaches significantly reduced the share value, then waiting for the dust to settle(reaction-news-cycle to complete) and the price to rise again.
So what's it going to look like 6 months from now? Your guess is as good as mine. Mine is: either absolutely nothing happens and the stock goes back up, or this finally gets something to be done about the garbage that is SSNs and/or credit reports (in which case I can't really imagine what happens to the stock price in any direction).