Final answer:
Closed-end company shares are likely to have a NAV that is 90% of their offer price since they can trade at discounts or premiums to their NAV on the open market.
Step-by-step explanation:
The type of investment company security that is the most likely to have a NAV (Net Asset Value) that is 90% of its offer price is a Closed-end company share. Closed-end funds issue shares at an IPO and then those shares trade on the open market. Unlike open-end funds (mutual funds), which are bought and sold at NAV, closed-end funds can trade at prices that are above or below their NAV, often leading to discounts or premiums based on investor demand. Hence, they might have a NAV that is 90% of their offer price if they are trading at a discount.