Berkshire (BRK.A)(BRK.B) has an enormous amount of money invested in Wells Fargo (WFC) and Goldman Sachs (GS), so the health of big banks is of great interest to Warren and Charlie.
In this interview Charlie says that he thinks the big banks should be more heavily regulated and simplified.
Allowing deposit taking banks to have derivative books was an horrific error.
Charlie thinks the temptation is too great for bankers who aren't regulated enough. He believes that the trading books are what get the banks in trouble.
There is no pending banking crisis, but eventually the banks with derivative books will get themselves back into trouble.