We provide the first empirical evidence on the determinants of the lending decision of venture debt firms, specialized institutions that provide loans to finance growth of high-tech startups. Building on existing field interviews and case studies, we design a choice experiment of the lending decision and conduct experiments with 55 senior venture lenders. We find support for the hypothesis that backing by venture capital firms substitutes for startups' cash flow. Furthermore, we illustrate the signaling effect of patents and their role as collateral to facilitate the lending decision.