Just like QE in the US, where financial system liquidity was boosted by the Fed injecting reserves into banks in exchange for sales of Treasurys and MBS, which fungible liquidity was then used for a variety of purposes including directly investing in risk assets as the JPM London Whale fiasco demonstrated, the PBOC announced that it will allow China's primary dealers to swap their holdings of perpetual bonds for central bank bills, and directly use those bonds as collateral to access certain PBOC liquidity operations.

By directly intermediating in the market, and effectively backstopping securities issued by local banks, this measure will increase the appeal of perpetual bonds to be issued by banks making them riskless for all intents and purposes, which can then be used to bolster capital cushions and thereby help relax a key current constraint on credit supply.