KEY POINTS
  • Walmart CEO Doug McMillon keeps a photo on his phone that lists the top 10 retailers in the U.S. over the past few decades.
  • Walmart has held the No. 1 spot since the 1990s, when it overtook Sears.
  • McMillon says the retailer maintains a "healthy paranoia" to stay ahead of rivals.
Walmart's Doug McMillon keeps a list of the top 10 retailers over the decades to remind him you have to innovate and adapt constantly.

Walmart CEO Doug McMillon keeps a photo on his phone that lists the top 10 retailers in the U.S. over the past few decades to remind him how so many companies come and go. Walmart wants to keep its No. 1 spot, which it's held since the 1990s when it overtook Sears.

"After learning from so many people ... we know that retailers come and go," McMillon told CNBC's Becky Quick Thursday, after he spoke in Washington, D.C., at the Business Roundtable CEO Innovation Summit. "Businesses grow and they don't change enough and they decline over time. Retailers do that on a bit of a faster cycle."