Maybe a silly question, but if the concept of a stable coin is to maintain market cap (i.e. coin price) by dynamically altering the supply and/or demand. (e.g. Tether, Ampleforth) then what is the potential for a return on investment? For example, if USDT is always about $1 what's the upside of investing in it if the price never goes up?
we don't call that investment. The stable coin is generated so that traders can secure the buying and selling of altcoins. When the price of altcoins suddenly drops, they can sell USDT and hold it. that is its only use.