INvestor Democracy is EXpected Act or the INDEX Act This bill establishes guidelines for passively managed funds (e.g., index funds) that vote shares on behalf of fund investors in proxy shareholder votes. Under the bill, these funds generally must vote shares on a proportional basis according to instructions from fund investors. The bill establishes an exemption for routine matters and matters requiring approval of a majority of outstanding securities. Additionally, the bill establishes a safe harbor from these requirements for investment advisers.