The state investment board shall invest and manage the assets entrusted to it with reasonable care, skill, prudence, and diligence under circumstances then prevailing which a prudent person acting in a like capacity and familiar with such matters would use in the conduct of an activity of like character and purpose.
The board shall:
(1) Consider investments not in isolation, but in the context of the investment of the particular fund as a whole and as part of an overall investment strategy, which should incorporate risk and return objectives reasonably suited for that fund; and
(2) Diversify the investments of the particular fund unless, because of special circumstances, the board reasonably determines that the purposes of that fund are better served without diversifying. However, no corporate fixed-income issue or common stock holding may exceed three percent of the cost or six percent of the market value of the assets of that fund.