This copy is for your personal, non-commercial use only. To order presentation-ready copies for distribution to your colleagues, clients or customers visit http://www.djreprints.com. Jarring stock market volatility has been a blunt reminder of the risks in retirement portfolios, and investors are understandably concerned. Many are second-guessing strategies that fattened their nest eggs in recent years and have fled to safety in money-market funds, which had their best monthly inflows in December since 2008. If recent volatility proves to be the precursor of a market dive, then those fleeing to safety will look smart.