Skip to navigationSkip to main contentSkip to right columnADVERTISEMENTReuben Gregg Brewer, The Motley FoolFri, July 31, 2026 at 8:35 PM GMT+2 3 min readCapital One (NYSE: COF) made a bold move by acquiring Discover. The big goal was to expand Capital One's transaction processing business, effectively taking on industry giants like Visa (NYSE: V) and Mastercard (NYSE: MA). But along with the processing business came Discover's other operations. There's an important interplay here that investors need to understand, summed up by one figure: Purchase volume.The headline number is a little misleadingCapital One's card business saw a 26% increase in purchase volume in the second quarter of 2026. That's a huge advance, but there are some important nuances to consider. The biggest nuance is highlighted by comparing the legacy Capital One business's purchase volume growth of 14% to the legacy Discover business's growth of about 2%. At first glance, that doesn't seem to square with the 26% overall increase. But the overall increase was driven by adding all of Discover's business to Capital One's existing business.Missed Nvidia in 2009? This Rare Signal Is Flashing Again. In 2009, a "Double Down" signal flashed for a little-known chipmaker called Nvidia. For the first time in years, that same "Total Conviction" signal is flashing for a company 1/100th the size of Nvidia. Continue »Image source: Getty Images.Looking at the legacy businesses, meanwhile, may cause some concern. Sure, Capital One's card business remains strong, but Discover's looks like it is struggling, relatively speaking. That's not exactly the right takeaway. Capital One is busy integrating Discover's card operations into its own operations. Part of that process is upgrading the credit quality of Discover's customer base. Management has called the current lull in growth a "brownout."The brownout is having the intended effect. Capital One's net charge-off rate for its card business fell 39 basis points between the first and second quarters. The 30-day delinquency rate fell 31 basis points. Hitting the pause button now will prepare Capital One to better deal with the next recession. It is just a matter of time before that recession arrives, so the brownout is really a wise business move.So far, Capital One's Discover deal is working out as plannedNotably, the brownout is just one of many aspects of the Discover integration process. For example, Discover cards are currently being migrated to the Capital One customer system. Capital One debit transactions have been moved over to the Discover processing platform. There are many moving parts, and the process is nowhere near complete. In fact, the company expects the process to last until at least the second half of 2027.Terms and Privacy PolicyEU DSA contactPrivacy & Cookie SettingsMore Info