He said that the market might now be set to push yields down another 10 or 15 basis points.
That pushed the yield, which moves in the opposite direction, higher.
The variables which pushed yields to this low level could not last forever.
He could not think of an "unexpected event" that might push the yield below 6 percent.
For example, aggressive buying of the 7-year note pushed the yield down to 6.10 percent on July 9.
The price of the 30-year bond plunged, pushing the yield up to 6.63 percent.
That hope gave a lift to the bond market, pushing yields and interest rates down.
Bond prices fell enough to push the yield on the 30-year Treasury issue to above 9 percent.
The price of the two-year note also fell sharply, pushing the yield up to 5.98 percent.
Bond prices dropped enough to push yields on the 30-year Treasury issue to about 9 percent.