Capital One announced plans to buy Discover Financial Services in a $35 billion deal that marries two of the largest credit-card companies in the U.S. and has the potential to shake up the credit card industry in a major way. WSJ’s AnnaMaria Andriotis explores what makes this deal such a game changer. Further Reading: - Capital One Is Buying Discover Financial for $35 Billion  Further Listening: - Inside the Capital One Hack  - The Fight Over Your Credit Card Swipe  Learn more about your ad choices. Visit megaphone.fm/adchoices