Reward-based crowdfunding enables credit-constrained entrepreneurs to raise money to develop and create innovative products. Crowdfunders’ low monitoring incentives open the door to fraud. In practice, fraud is surprisingly rare. Strausz (2017) proves that crowdfunding implements the optimal ex post individually rational mechanism design outcome in an environment with entrepreneurial moral hazard and private cost information. However,ex post individual rationality precludes all crowdfunding unless fraud can be prevented with certainty. Actual crowdfunding tolerates some fraud. We show this (i) generates strictly higher profits and welfare, but (ii) cannot implement the optimal ex interim individually rational outcome. © 2019