The longer you invest, the more potential your money has to compound interest. If your portfolio has not fully recovered from losses in recent years, you may wish to consider a more aggressive allocation to make up for lost ground and get back on track to accumulating wealth.
However, given lessons learned in stock market investing, it is important to remember more conservative retirement strategies typically have only a portion of the assets invested in the stock market. Other allocations should be set aside for more conservative investments and/or secured income contracts such as annuities.
Annuities are long-term vehicles designed to generate supplemental income during retirement. They have minimum guarantees backed by the strength and claims paying ability of the issuing insurance company. After all, the last thing you want to do is lose more ground during the next market correction.