The purpose of this study is to identify the best timing for private firms to go public. Private firms possess an option to go public at the time their managers believe it would be a valuable strategy. In the same way, exchange traded companies also have the option of issuing more equities or even taking them over. In this sense, the theory of real options can be applied in order to value management flexibility in an uncertain and dynamic ambience in which traditional methods such as net present value fail to evaluate investments. For the management team, the more uncertain the market is, the more value it adds to the option to wait and postpone the issuance. Given that stock prices fluctuate randomly over time and follow the Geometric Brownian Motion, the Monte Carlo Simulation provides the forecasted stock prices to help the decision making process and also to value the timing option. Therefore, the entrepreneur is willing to wait for positive price shocks before taking the firm public. As a consequence of optimally exercising the timing option IPOs should occur after abnormal price increases. Any firm contemplating an IPO should factor the timing option into the decision. The main reason for the IPO can be either capital raising or the desire to increase the shares’ liquidity but, in all cases, the benefit of going public should be greater than the value of the timing option and issuing shares from private equity.