Housing finance is broadly resilient, but pockets of vulnerabilities exist. Mortgage finance is dominated by domestic systemically important financial institutions (D-SIFIs) and supported by the government via mortgage insurance, securitization guarantees, and other policies. With a market share of about 70 percent, D-SIFIs focus on prime borrowers, and their lending is backed by their strong balance sheets. The smaller (uninsured) non-prime lending segment is largely served by smaller banks and prudentially unregulated lenders, which are comparatively less resilient. Some of these lenders rely on less stable, higher-cost funding such as brokered deposits or redeemable equity, and their lending is concentrated in regions with large housing market imbalances. Market concerns about the business model of non-prime lending were manifested by the liquidity crisis at a mid-sized deposit-taking institution in 2017.