The opposite happens if USDP is below the peg, then the stability fee is increased which lowers the supply as it makes borrowing more expensive. Thus, in case USDP is trading below US$1, stability fees would be increased to limit the number of new CDP openings. The current CDP owners would be incentivized to repay their debt positions at lower price. Altogether, it will shrink USDP supply, thereby taking the USDP out of circulation and driving the price up.