There's been quite a bit of consolidation in the banking industry over the past 25 years, and this is especially true with the "big four" U.S. banks.

In this segment from Industry Focus: Financials, host Michael Douglass and Fool contributor Matthew Frankel explain how some of the big banks have acquired competitors, and in some cases been acquired themselves, on the way to becoming the big banks of today.

A full transcript follows the video.

This video was recorded on June 25, 2018.

Michael Douglass: Matt, let's start by going to the past and some of the major changes we've seen in the banking industry over the past 25 years. One of the big ones that we were talking about before we hopped on air today is, of course, consolidation.

Matt Frankel: Yeah, definitely. One of the big things that's happened over the past 25 years is that the big banks have gotten bigger. We now have what are known as the Big Four banks in the U.S. -- Citigroup, Bank of America, Wells Fargo and JPMorgan Chase. All of those have grown substantially through acquisitions, not just from the financial crisis, which saw a lot of consolidation, but beforehand. Actually, three of the four were actually acquired themselves, and the acquiring companies just decided to keep the names because they were more recognizable.

Just to name a couple of cases: Wells Fargo picked up Wachovia along the way; JPMorgan, Bear Stearns, Washington Mutual; Bank of America picked up a bunch, U.S. Trust, Countrywide Financial, Merrill Lynch. You've heard before the financial crisis that a lot of these banks were becoming too big to fail, and it seems that they've actually become bigger as a result of the financial crisis. That's been one big trend, a lot of consolidation in the industry over the past 25 years or so.