TheStreet's Jim Cramer says he is looking at JPMorgan when the yield is at 3.25% and does not understand why investors are "throwing it away." But, Cramer says the execution at JPM was not that good. Wells Fargo's execution, on the other hand, is "terrific," says Cramer, but the stock is priced for perfection. Cramer thinks JPMorgan and Wells Fargo will come down, but the whole banking sector is now "for sale." However, Cramer warns that the bottom is not here, and investors should not bottom-fish.