We study the rise of fintech and non-fintech shadow banks in the residential lending market. The market share of shadow banks in the mortgage market has nearly tripled from 2007-2015. Shadow banks gained a larger market share among less creditworthy borrowers, with a tilt towards refinancing mortgages. Shadow banks were significantly more likely to enter markets where traditional banks faced more regulatory constraints. This suggests that traditional banks retreated from markets with a larger regulatory burden, and that shadow banks filled this gap. Fintech firms accounted for almost a third of shadow bank loan originations by 2015. To isolate the role of technology in the decline of traditional banking, we focus on technology differences between shadow banks, holding the regulatory differences between different lenders fixed. Analyzing fintech firms’ entry and pricing decisions, we find some evidence that fintech lenders possess technological advantages in determining corresponding interest rates. More importantly, the online origination technology appears to allow fintech lenders to originate loans with greater convenience for their borrowers. Among the borrowers most likely to value convenience, fintech lenders command an interest rate premium for their services. We use a simple model to decompose the relative contribution of technology and regulation to the rise of shadow banks. This simple quantitative assessment indicates that increasing regulatory burden faced by traditional banks and financial technology can account, respectively, for about 55% and 35% of the recent shadow bank growth.