Money market funds came about in the early 1970s.[12] Individual retirement accounts and 401(k)s began investing in mutual funds after the Revenue Act of 1978.[13] Exchange-traded funds (ETFs) brought even lower costs to investors in the 1990s.[14] Fund Dilution and Liquidity The 1940 Acts along with SEC rules to implement them addressed the failures of the Depression-era investment funds and have lowered the risk of financial fires spreading from funds. [read post]