"Technological innovation is disrupting traditional business models of many industries, putting a lid on prices and influencing inflation in the economy overall," BlackRock Chief Investment Officer Rick Rieder wrote.
Citadel Securities will start making markets for investors in all older Treasuries, broadening an effort it started in February.
Treasury Secretary Steven Mnuchin has formed an internal working group to study maturities of 50- and 100-year debt.
Bond traders are reassessing their views of the Fed after policy makers stuck to their interest-rate path in the face of disappointing economic data.
The bond market continues to defy the Wall Street consensus.