(not sure this is the right stack exchange to ask crypto-economics questions, if not please direct :) )
Why are stable coin values not exactly the value they're pegged against?
For example as of this post:
USDC: $.99967 (https://coinmarketcap.com/currencies/usd-coin/)
USDT: $.9986 (https://coinmarketcap.com/currencies/tether/)
GUSD - I saw Gemini's stable coin GUSD rose to $1.14 at one point in Dec 2018.
If each token is pegged to a dollar in reserves (talking about collateralized stablecoins not algorithm ones like DAI), and at any time I can redeem my token for that $1, what's creating that difference in value?