Underwriter compensation in an IPO, expressed as a percentage of gross proceeds — typically 3-7% (higher for smaller deals; ~7% has been the de facto standard for sub-$500M IPOs). Allocated three ways: management fee (~20%, divided by economics among bookrunners), underwriting fee (~20%), and selling concession (~60%, paid to whichever syndicate members actually placed the shares). Direct listings eliminate the gross spread entirely.