The economy is growing. Businesses are hiring. Stocks are soaring. And banks are sitting on big piles of cash.If only they had a better place to put it.Lingering supply chain problems and anxiety over the potential for the Delta variant of the coronavirus to upend the economy again have pared back borrowing by businesses. And consumers flush with cash thanks to government stimulus efforts aren’t borrowing heavily, either.So banks have largely been left to invest in one of the least lucrative assets around: government debt.Rates on Treasury bonds are still near historically low levels, but …
