What is a volume-based fee reduction for traders using the Luno exchange?

Could you elaborate on the concept of volume-based fee reduction for traders utilizing the Luno exchange? Specifically, how does it work? Is it a reward system where traders who conduct a higher volume of trades receive a discounted rate on their transaction fees? Or is it a graduated scale, where the more volume a trader accumulates, the more significant the fee reduction becomes? Additionally, are there any thresholds or minimums that traders must meet to qualify for this type of fee reduction? Understanding the specifics of this incentive structure would help traders determine if it's a viable option for them to increase their trading activity on the Luno platform.