Organizations take the pronoun “it.”
Example: CFA Institute revised its policy on smoking in 1991.
If a pronoun is referring to an individual and you do not know whether the person is male or female, use the “he or she” forms. You can also vary the forms within a text (i.e., balance the use of “he” and “she” or “his” and “her”).
Example: If an individual places all of his or her assets in one stock, then that portfolio is not diversified. One investor put all his money in stocks; another investor put all her money in bonds.
To simplify and keep sentences from being overloaded with pronouns, try to switch to the plural.
Example: Change “if an investor wants his or her portfolio to be . . .” to “if investors want their portfolios to be . . .”