The yield on the 30-year long bond had fallen almost half a percentage point since March 31, a large fall for less than six weeks.
This is the largest fall since the fall between 1974 and 1979.
And Brazil's gross domestic product is expected to drop 4.7 percent this year, its largest fall ever.
These episodes depleted its funds and led to a large fall in membership.
The largest fall, of 86.2 percent, came in the Depression, from 1929 to 1932.
It was home to the area's largest fall fair (agriculture exhibition) for many years.
However, the election was notable for a large fall in voter turnout.
The previous largest fall was in April 1978, when the underlying level fell $2.115 billion.
There is another fall, larger and with three levels, in the vicinity.
It is a large fall with its water source in Burma and runs full during the late rainy season.