This paper addresses the investment and financing decisions of an entrepreneur entering into an option-for-guarantee swap. We discover that the swap greatly increases the value of the option to invest. The entrepreneur first accelerates and then postpones investment as the funding gap rises. Guarantee costs increase with project risk when funding gaps are small or large enough and otherwise the opposite holds true. Surprisingly, the higher the project risk, the more the entrepreneur borrows. Thanks to the swap, the entrepreneur raises much more funds than required to invest and the optimal leverage is much higher than predicted by previous models.