The report noted that passive portfolios diversified in international asset classes generate more stable returns, particularly if rebalanced regularly. State Street Global Advisors has long engaged companies on issues of corporate governance. Passive managers can vote against a board of directors using a large number of shares. Being forced to own stock on certain companies by the funds' charters, State Street pressures about principles of diversity, including gender diversity. The Bank of America estimated in 2017 that 37 percent of the value of U.S. funds (not including privately held assets) were in passive investments such as index funds and index ETFs. The same year, BlackRock estimated that 17.5 percent of the global stock market was managed passively; in contrast, 25.6 percent was managed by active funds or institutional accounts, and 57 percent was privately held and presumably does not track an index. Similarly, Vanguard stated in 2018 that index funds own "15% of the value of all global equities". See also Investment management Active management Exchange-traded fund Buy and hold Index fund Enhanced indexing Relative return Value investing Investment style References Further reading Burton G. Malkiel, A Random Walk Down Wall Street, W. W. Norton, 1996, John Bogle, Bogle on Mutual Funds: New Perspectives for the Intelligent Investor, Dell, 1994, M. Nicolas J. Firzli, "Passive Play: Disenchanted Asset Owners Going Low-Cost as the ‘Age of Austerity’ Lingers", Revue Analyse Financière 54 (2015): 68-70. Mark T. Hebner, Index Funds: The 12-Step Program for Active Investors, IFA Publishing, 2007, External links The Active vs Passive - unresolved issues. The Future of Investment Management Lazy portfolios on Bogleheads.org Investment management