Why invest in this fund? I have been asking myself this for the past few months and I have come the the conclusion that an investor should stay away. This fund is supposed to move its allocation between stocks, bonds, and money markets to find the best returns for its share holders. For this entire year that the stock market has been on a wild ride, the fund has been in 100% stocks. I do not know what algorithms they use to justify that, but they were 100% wrong. Will it go to 100% bonds when the stock market goes up again. Why not simply go with a cheaper Index 500 fund? On the Vanguard summery page about this fund, it states:

Seeks to maximize long-term total return (share price growth plus income) while incurring less stock market risk than a fund made up entirely of stocks.

Well, they didn't. If you are thinking about investing in this fund, just pick another.