The Australian Financial Markets Association, which administers the bank bill swap rate and publishes the rates on its website, is confident BBSW has not been compromised by any traders attempting to manipulate it.The US Commodity Futures Trading Commission's has reported that traders at investment bank UBS tried to manipulate Australia's BBSW, along with other financial market benchmark interest rates.AFMA's executive director, David Lynch, said BBSW was based on two key concepts: it is a measure of rates for paper issued by four prime banks (the major banks); and it is a measure of observable trades."BBSW is much less susceptible to manipulation that Libor," Lynch said.Up to 14 traders in prime bank paper (BBSW panellists) submit observations for all maturities each day. AFMA staff check submitted rates for implausible contributions, and if they identify any, they contact the panellists to confirm the rate.The BBSW rates are trimmed arithmetic means; the high and low rates for each term are eliminated progressively until only six rates remain for each term.Lynch said: "We have analysed the rate contributions and found that there is a very small variance after trimming. The spread of accepted rates for BBSW was within one basis point 98 per cent of the time in 2012."The range of rates that might make up Libor is much broader. Libor relies on estimates of what each bank believes it could receive in the market.Lynch said that what the CTFC report was not news. It was issued in December and reported on the Compliance Complete news site on January 8.AFMA's focus now is on new standards for financial market benchmarks, which will be issued by the International Organisation of Securities Commissions later this month.