In crises of liquidity and solvency, central banks can provide liquidity to support illiquid banks. Financial intermediaries will become both insolvent and illiquid. Practitioners struggle with the valuation of illiquid securities. Recently, many hedge funds have turned away from investing into restricted illiquid investments. Securities that are illiquid in the market are classified as "hard". First, they help provide access to funds for those entities with illiquid mortgage-backed securities. Extensions continued for banks to exit illiquid investments. The bias ratio is also useful to detect illiquid assets forensically. On August 11, 2016, several large banks requested a 5-year delay to exit illiquid investments. Almost all documented anomalies focus on illiquid, small stocks. Glass and Willis criticized all forms of "illiquid loans" including bank real estate lending. M1 includes only the most liquid financial instruments, and M3 relatively illiquid instruments. This resulted in a fragmented and sometimes illiquid market. This can have significant risk as the market for the illiquid may have moved. These types of goods tend to be illiquid in nature.