An effective portfolio disclosure regime must balance both its costs and benefits across the entire financial services industry. This study examines a number of disclosure regimes with respect to accuracy and susceptibility to copycat behaviour in an environment absent of mandatory disclosure. We find that periodic portfolio disclosure tends to underestimate true excess performance as well as idiosyncratic risk in top-quartile fund managers, with longer inter-reporting intervals tending to result in greater differences. Copycat funds following the disclosed holdings of top-tier managers significantly underperform their target funds, while copycats following bottom-tier managers significantly outperform their target funds. Our findings suggest that periodic reporting at monthly intervals or longer would not affect fund alpha generation.