# Discount Offer

**'Discount offer' is a mechanism that is only activated in Adjustment Mode.** In this mechanism, users can purchase margin tokens like xiBGT using ZUSD, and when AAR is lower than AART, the discount for purchases gradually increases over time. It is a Dutch auction-based exchange.

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**Let's take the xiBGT discount offer as an example:**

* In the Adjustment Mode, when AAR is between 101% and AART, the formula for trading xiBGT with ZUSD is:

$$\Delta xiBGT = \frac{\Delta ZUSD \times M\_{xiBGT}}{M\_{iBGT} \times P\_{iBGT} - M\_{ZUSD}} \times (1 + r)$$

Where ( r ) is the compensation coefficient, which gradually increases over time.

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Additionally, to prevent extreme volatility risks, when the AAR falls below 110%, the 'Discount offer' will be paused for half an hour, and it will resume after one hour.
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* When AAR falls below 101%, the formula for trading xiBGT with ZUSD changes to:

$$\Delta xiBGT = \frac{\Delta ZUSD \times M\_{xiBGT} \times 100}{M\_{ZUSD}}$$

* When AAR rises over AART, it enters Stability Mode, and the discount offer ends.