Abstract Until now, IPO market timing has been mostly associated with a varying number of IPOs in certain periods of “hot” and “cold” issue markets. We would like to offer a different perspective. We focus on a speed of the IPO process, after the decision to go public was actually made. Our hypothesis is that in “hot market” managers will tend to minimize the time necessary to go public in order to take advantage of high valuations as quickly as possible. On the contrary, if the firm is not ready with the IPO on time and in the meantime the market falls during the going-public process, managers will tend to delay the IPO hoping that the good market conditions will come back soon. We argue that such a behavior might be attributed to the disposition effect among firms' managers. We find a statistically significant negative correlation between the market return and the speed of the IPO process. The absolute correlation coefficient is higher when the market return is calculated 90 days prior to the Approval Date of the prospectus than when it is calculated 90 days after the Approval Date. Hence, a vast part of the market influence on the speed of the offering process has its origin at the time when offering is formally not possible yet. External factors occurring after the Approval Date seem to be less important than the managerial decision influenced by observation of the market situation prior to the Approval Date. We also find that for firms debuting faster than the median of our sample, the average market return in the period between the IPO date and the median is positive. On the other hand, in the group of slower firms, the average market return in the period between the median and the IPO date is negative. There is an analogy between firms – debuting too fast in bullish market and too slow in bearish market, and investors – selling winning stocks too quickly and keeping falling stocks for too long in their portfolios. Both managers and investors seem to be biased by the S-shape utility function, as predicted by the prospect theory of Kahnemann and Tversky (1979) .