Both funds invest in issues of short maturity, as made clear by their names.
The city said it hoped the shorter maturity would save about 50 basis points in interest.
As these bills were of short maturity (up to three months) they "rolled over" rather quickly.
Most recent increases, he added, have come from the shorter maturities.
The gains were less in the shorter maturities for notes.
Second, the Mexican government had also substantially decreased the already short maturity of the debt.
Issues with shorter maturities, however, continued to post gains throughout the day.
With such concerns in the market, the inflation reports this week are more important for shorter maturities.
"Invest in shorter maturities - two or three years at most."
When the spread is narrowing, they sell short maturities and buy long ones.