AOA is one of four iShares Core target-risk ETFs. It offers an all-encompassing aggressive asset-allocation strategy in a fund-of-funds wrapper. The index invests across asset classes and subgroups using other iShares ETFs. The use of ETFs in the basket allows investors to quickly understand how the fund is positioned. It also keeps the focus on top-down allocation rather than bottom-up security selection. AOA plays it straight with large allocations to vanilla versions of major asset groups: US large- and midcaps, international equities and broad bonds. The fund also allocates in smaller proportions to emerging market equities, US small-caps, high-yield bonds, REITs and TIPS. What makes the fund aggressive is its 80% allocation to equities and 20% to fixed income. AOA and its kind differ from target-date funds in that the asset mix is relatively static, rather than following an increasingly conservative glidepath. The index is rebalanced semi-annually starting October.