As has become its practice, the Commonwealth bank released its unaudited trading update for the first quarter of its 2017/18 financial year to allow investors some comparison across all major bank results.CBA appears to have shrugged off reputational and regulatory woes when it reported an unaudited statutory net profit of approximately A$2.80 billion in the quarter, along with unaudited cash earnings of approximately $2.65 billion in the quarter, up six per cent.The bank emphasised - as indeed does Banking Day - that while these are indicative of trends in CBA's performance, the report should not be relied upon for investment decisions.The numbers were published via an ASX announcement yesterday, and relate to the quarter ended 30 September 2017, in comparison with the average of the final two quarters of CBA's year - that is for the year ended 30 June 2017. On that basis, operating income grew by four per cent, with banking income supported by improved margins. "Home lending growth was managed within regulatory limits," the bank said. Trading income was broadly flat, while funds management income decreased slightly, with lower margins partly offset by the benefit of positive investment. Insurance income improved "reflecting fewer weather events and the non-recurrence of loss recognition," CBA noted.Group net interest margin was higher in the quarter, driven by asset repricing and reduced liquid asset balances. As with CBA's rivals, the mortgage repricing benefits were partly offset by the impact of the banking levy, higher funding costs and competition."Expense growth of four per cent includes provisions for our current estimates of future project costs associated with regulatory actions and compliance programs," CBA predicted.Other operational and funding highlights for the quarter ended 30 September were: •    credit quality of the Group's lending portfolios remained sound - for instance, the loan impairment expense of $198 million in the quarter equated to 11 basis points of gross loans and acceptances, compared to 15 bps in FY17; •    corporate loan impairment expense was substantially lower in the quarter, and troublesome and impaired assets were lower at $6.1 billion, with broadly stable outcomes across most sectors;•    consumer arrears were seasonally lower but continued to be elevated in Western Australia, while prudent levels of credit provisioning were maintained, with total provisions at approximately $3.7 billion;•    CBA's funding and liquidity positions remained strong, with customer deposits funding 68 per cent of the group's capital needs (increasing by 4.8 per cent, quarter on quarter) and the average tenor of the wholesale funding portfolio sitting at 4.4 years.; and •    the Group issued $9.5 billion of long term funding in the quarter, including a 30 year US$1.5 billion issue - with CBA claiming this as a first for an Australian major bank.Key Group ratios, as at September 2017:•    net stable funding: 107 per cent at September 2017;•    liquidity coverage: 131 per cent, with liquid asset balances and net cash outflows moving by similar amounts in the quarter; •    liquid assets: $132 billion in total;•    leverage: 5.2 per cent on an APRA basis