While Islamic scriptures clearly prohibit profiting from the poor, supposedly sharī'ah-compliant Islamic financial and exchange laws circumvent prohibitions and limitations on ribā, monopolism, debt, and risk while failing to address the fundamental purpose behind the prohibitions—mitigating poverty. This work provides a historical survey of the principles that shape Islamic finance and exchange laws, reviews classical and modern interpretations and practices in the banking and exchange sectors, and suggests a normative model rooted in the interpretation of Islamic sources of law reconstructed from paradigmatic cases. Financial systems that overlook the nexus between poverty and usury harm both the economy and poor and middle class consumers and investors rather than addressing the causal relationship between interest-charging models and poverty. This work shows how Islamic Financial Institutions (IFIs) have failed to meet the social requirements they were intended to address and also presents a theoretical framework for Islamic finance and exchange laws that proscribes usurious transactions involving people caught in the cycle of poverty and need.