Institutional investors usually make IPO indications of interest that are several times larger than what they really want, hoping to end up with a reasonable allocation. While this strategy works most of the time, sometimes the order book doesn't build the way the lead manager hopes. At this point, the lead manager can cut the price of the offering, which might increase demand, cut the size of the offering, or give the institutional investors all the stock they requested. This is getting stuffed. Institutional investors who get stuffed usually think there is something wrong with the stock and sell.