The number of open contracts in 10-year Treasury futures fell after the release of CPI data.

JPMorgan Chase & CoThe proportion of customers holding neutral positions in US Treasuries has risen.

Growing concerns about inflation are causing Treasury investors to shy away from Treasury futures.

After the data showed that CPI rose more than expected in June, US bond futures accelerated their decline on the day, further exacerbating the selling pressure on the bond market. The number of open 10-year Treasury bond futures due in September 2021 fell 1.3 per cent to 4.15 million, the lowest on record. The reduction of 53000 contracts is equivalent to $5 billion in 10-year Treasuries, and there are currently $117 billion in outstanding 10-year Treasuries.

The number of 10-year Treasury futures contracts still in use has fallen by 266165 from a peak on June 16.

The CPI report further undermines confidence in the Fed's position. The Federal Reserve thinksQualcomm IncThe inflationary trend is unlikely to continue and no monetary policy action is required.

Minneapolis Fed President Neel Kashkari and San Francisco Fed President Mary Daly reiterated this view after the inflation data were released, but Federal Reserve Chairman Powell said in congressional testimony on Wednesday that there was still a long way to go to achieve "substantial further progress."BlackrockCEO Larry Fink said inflation would not be temporary, and the company announced a collective pay rise for its employees.

The withdrawal of 10-year Treasury futures also reverberated in the spot market, with JPMorgan Chase & Co's latest weekly Treasury customer survey showing a decline in the number of customers holding net short positions, with the neutral ratio at the highest level since early May.