Comparing the Marginal Cost of Wholesale Funds for BAC and WFC Next, we look at the updated marginal cost of funding for two key Berkshire Hathaway investments, Wells Fargo & Co. and Bank of America Corporation. First, we look at the spreads on Wells Fargo & Co. (WFC) bond issues and compare them with the U.S. Dollar Cost of Funds Index. Using a simple average of the difference, we find that Wells Fargo & Co. has a marginal cost of funds 0.215% BELOW the U.S. Dollar Cost of Funds Index. Bank of America Corporation, by contrast, has a marginal cost of funds 0.114% above the U.S. Dollar Marginal Cost of Funds index. This represents an advantage for Wells Fargo & Co. of 0.215% + 0.114% = 0.329% over the marginal cost of funds for Bank of America, about 1 basis point higher than we found two days ago. Ironically, the marginal cost of funds for Berkshire Hathaway, at 0.337% below the U.S. Cost of Funds Index, is lower than the marginal cost of both banks in which Warren Buffett has invested.