The top 3 are the old brick and mortar banks... doesn't surprise me in the slightest given historical typical consumer behavior.
Costco portfolio maybe, but remember we're the outliers here, originally most people run their entire financial lives through the institution they started with and I don't think that's changed astoundingly much other than maybe the newer generations who have access to much more information.
But versus Chase and BoA? Citi has many many fewer branches.
Think that's true now but historically before BOFA acquired NationsBank and before Chase started putting up a new branch every 2 miles in some places (that was about 5 years ago out here) when the majority of population was getting their bank accounts and credit cards with the institutions likely their parents had relationships with?
Not so certain about that and at least pre-crisis and divestiture Citi had a staggering amount of assets under management; then again if I had to guess Costco cardholders are probably on the order of 30-40M? That is a lot admittedly.
Makes sense then... BofA and Chase seem to be in branch wars in my neck of the woods; there's one spot that you can even almost SEE two BofA branches from each other they're so close!