The Commonwealth Bank of Australia (CBA) slashed its capital charge for interest rate risk in the banking book (IRRBB) almost in half over the last six months of 2018 following an overhaul of its US dollar exposures and a shortening of the term of its capital investments.

IRRBB risk-weighted assets fell A$10.5 billion ($7.5 billion) or 43% to A$13.9 billion over the six months to end-December. The capital charge, calculated as 8% of RWAs, now stands at A$1.1 billion.

The bank said the drop