This is a hard question to answer. Ultimately, peg maintenance is not about instantly buying back every NBT being sold for less than $1 as much as it is to ensure a general concept that NBT is worth $1. If any customer says that they have trouble selling their NBT for a reasonable price, we need to seriously listen to them. Therefore, the liquidity tiers are not necessarily about being able to buy back every NBT, only the NBT that are being sold. This distinction is vital, as it allows us to separate NBT like those stored for use by B&C and Pool Operators that will be released with regularity based on a centralized contract.
Tier 1 is used to generate confidence in the NBT price and to give higher tiers an indicator for market activity. The size need only be big enough to give observers a clear indication of which direction the peg is leaning. As such, it is mechanically chosen for each individual market instead of being a percentage of NBT in circulation. As Nu grows this will naturally grow because shareholders will feel more willing to spend money and expand to new markets.
Tier 2 is used to recover and refresh the peg. This tier is still abstract to me, there’s a point to be made here about MoD’s exit and entry gateways being mostly T2. Anyway, I think the size of this tier is determined by causality more than being something we can control.
Tier 3 is something we could dare give a number to, but we have no mechanisms to truly control this. I’d suggest we should have something like 10% of the NBT marketcap in this Tier, controlled by trusted custodians. However, my trusted custodian proposal doesn’t look like it’s going to pass, so I’m not sure how shareholders might remedy this.
Don’t forget that Tier 4 already has 15%, and many people have been talking about additional mechanisms that may increase this (using distributed reserves or making a PPC reserve)
