Indication of Interest (IOI)

There's an IPO coming. A hush, all over the world.

When an underwriter markets an IPO, they being with a lot of whispering...and golf. Then there's a red herring marketing document that hungry investors devour (or that bored investors skim). The broker then calls, "So, bud...how you feelin' on whatever.com?" And the bud then says, "Meh," or "How can I buy every share possible, first print, after my allocation?"

That is, the buyside buyer of the IPO indicates her interest to the broker, who "builds a book" of buyers with a kind of bell curve set of indications from very interested...to a lotta meh. All relative indications of interest.