It stands for “certificados de tesoreria”, which is a peso-denominated short-term treasury bill (zero coupon bill) issued by the Mexican authorities as a monetary policy instrument and a means to cover financial needs. The first government peso-denominated fixed rate treasury bond (cetes) was issued in 1978. Maturity for cetes bonds is typically 28, 91, 182, or 364 days. However, the market activity in cetes bonds is mainly concentrated on 91-day maturities. Historically, zero coupon bills (cetes) and fixed coupon bonds (bonos) have shown the highest turnover, while inflation-indexed securities (udibonos) barely trade because they are usually held until maturity by investors such as pension funds, which aim to hedge the liability side of their balance sheets. Another type of government securities, floating-rate coupon bonds (bondes) are purchased by brokerage houses which finance their positions through the use of relatively short-term repos, and thus have more liquidity than udibonos.