Four frog coins, chosen once and fixed. Every round the bank claims whatever trading fees this coin has thrown off, buys whichever of the four is furthest below its quarter share, and sends the whole lot out to holders under its own signature. It never sells and it keeps nothing. What it bought is in your wallet, not in a treasury.
Every round settles on chain under its own signature and is published here. The disclosure sets out in full what holding FROGBANK does and does not get you.