The AURA rewards system is unrelated to any AURA you have purchased on the exchange. The rewards system is designed to generate liquidity by incentivizing market makers to add orders to the books. In this program market makers are granted AURA in proportion to the amount of trade fees paid on filled limit orders. The more limit orders you have filled, the greater your percentage of the rewards pool.
20% of our total token supply is dedicated to this program, and 1% of the remaining amount is distributed each month. You can see the current amount available this month under total reward pool this period. The exact amount you receive each month is only known at the end once the trading period has ended. This explains why your earned reward amount dropped over time. As others traded the overall volume increased but your volume stayed the same (we’ll add the word “projected” in front to make this more clear).
Earning rewards is unrelated to the amount of AURA you have in your wallet or on the exchange, but it does tie in with our other token, IDXM. This token is a membership for IDEX that entitles the holder to free trades until 2021, or a 2x multiplier on the AURA rewards.
You can also chose a proportional mix of both, such as 50% off trade fees and 1x rewards (rewards are a function of fees paid, so the greater the discount the less rewards). The designation is set using the slider in the right side of your screenshot.
Additionally, if you have only part of a membership then the benefits are fractional (0.5 IDXM entitles you to 50% off trade fees or 1.5x rewards). To use the membership simply hold the token in the wallet you are using for trading on IDEX.
Let me know if you have any other questions as you dig in, happy to provide more info!