Emerging antibiotic resistance is a major global health challenge, imperilling decades of biomedical advances in treatment of infections, cancer, and safe surgery. Antibiotic shortages contribute to this threat. R&D of new agents and secure supply of older generic antibiotics have come under pressure as returns demanded by investors have driven exits from less profitable therapeutic areas including antibiotics. Large pharmaceutical firms are pulling out altogether while new antibiotic development relies on financially vulnerable small and medium sized companies (SMEs). Several SMEs have gone bankrupt as they sought funding to commercialise newly approved formulations. Consequent access challenges for both novel “new” and extant “old” antibiotics merit deeper comparative research. However, economic incentives for antibiotic production are typically studied in the context of insufficient funding of R&D and typically seek traditional market solutions. This narrow focus on the so-called ‘empty pipeline’ for new therapeutics ignores the broader contribution of financialised profit motives to global shortages and the feedback loop from unprofitable old antibiotic markets into the commercial (non-)viability of novel antibiotics. ‘The market’ has so far failed to provide shortage mitigations. This thesis therefore examines the impact of financialisation on antibiotic markets using a mixed methods approach. Analysing qualitative and quantitative financial sources, coupled with evidence of antibiotic use in medical practice from clinical research, I develop two case studies of antibiotic market failure: (i) failed supply of “old” antibiotics studying the global shortage of piperacillin-tazobactam (2010-2020); and (ii) failed creation of viable post registration markets for “new” antibiotics studying the unsuccessful commercialisation of plazomicin (2005-2019). This research contributes understanding of how investors’ financial return expectations may contribute to a global shortage of critical antibiotics and the vulnerability of the SME-led antibiotic pipeline. Four key themes emerged: i) cashflow challenges faced by SMEs upon which the world relies for antibiotic innovation and pipeline dependence on financial investors for survival; ii) opacity and financial vulnerability of antibiotic supply chains and a lack of policy oversight over consequent risks to resilience of global supply; iii) the emerging role of China in global antibiotic infrastructure beyond ingredients (APIs) into innovation; and iv) conceptual weaknesses in the way investors in antibiotic infrastructure are portrayed leading me to develop novel framing of the ‘antibiotic investment ecosystem’. In conclusion, rather than a conventional focus on linear movement of molecules through pipes, my research suggests a need for additional policy frameworks to connect investors (public and private) in order to improve antibiotic innovation, supply and access going forward.