This chapter focuses on an alternative explanation for the wave of accounting and financial reporting irregularities that surfaced in 2001–2002: namely, that the gatekeepers failed. That is, the professionals who serve investors by preparing, verifying, or certifying corporate disclosures to the securities markets that acquiesced in managerial fraud; not in all cases, to be sure, but at a markedly higher rate than during the immediately preceding period. While the gatekeeper concept will be discussed and refined later, this term certainly includes the auditors, securities analysts, and securities attorneys who prepare, review, or analyse disclosure documents. Part II of the chapter develops competing, but complementary, explanations for gatekeeper failure. Part III maps out the range of strategies available to regulators. Part IV proposes alternative reforms intended to make gatekeepers more responsive to the interests of investors.