We access electronic share settlement records for each subscriber and aftermarket investor in 419 Australian IPOs to investigate whether initial subscribers flip their allocations, and we relate this flipping behaviour to issuer, shareholder, underwriter and market characteristics. We find that the main determinants are underpricing (consistent with the disposition effect, i.e., a tendency to realise gains before losses), whether the IPO market is “hot” (a proxy for the representativeness heuristic) and ex ante risk characteristics. When flipping is analysed separately for underpriced and overpriced IPOs we find that the most overpriced IPOs are flipped more than the less overpriced ones, a result which contrasts the disposition effect. This result is due to the action of institutional, rather than individual, investors. We also relate flipping activity to the firm's long-run return, and find that the flipping behaviour of large (informed) investors is unrelated to long-run returns, while uninformed investors consistently flip more of the IPOs that have better long-run returns.