Abstract (EN)

We document a robust buy/sell asymmetry in the choice of the broker in the IPO aftermarket: institutional investors are less likely to sell than buy through the lead underwriters. Consistent with investors hiding their sell trades, the asymmetry is the strongest in cold IPOs and it is limited exclusively to the first month after the issue. Contrary to the conventional view, the intention to flip IPO allocations is not an important motive for hiding sell trades from the lead underwriters; institutions that sell shares through non-lead brokers tend to have bought them through the lead underwriters in the IPO aftermarket, consistent with institutions breaking their laddering agreements. We find that hiding sell trades is an effective strategy to circumvent underwriters' monitoring mechanisms: the more institutions hide their sell trades, the less they are penalized in subsequent IPO allocations.