I examine the syndicate structure of 460 IPOs issued between 1998 and 2000 of which 285 have been sued for laddering. Laddering is a deceitful practice in which the underwriting investment bank allocates primary shares at the offer price to initial investors conditional on these investors committing to purchase additional shares in the aftermarket on pre-determined dates. Strong evidence is found that laddered IPOs have a smaller and less concentrated syndicate structure compared to non-manipulated IPOs. This finding provides evidence of a closer profit sharing and complicit collusion between...