Volatility-based Market-timing & Tactical Asset Allocation Presentation at Attica Bank, Athens, for the Hellenic Chapter of MTA We investigate how US stockmarket volatility indices such as the VIX, and other technical or stochastic econometric estimations of historical volatility can be used to create a series of indicators that allow for a more efficient reallocation of portfolio funds between low and high risk assets. Our results show that drawdowns and portfolio risk can be reduced considerably while returns are increased. Our strategy is characterized by low computational complexity and shows resilience to both 2001 and 2008 market crashes. Moreover, it can form the core of an algorithmic-based investment approach for small, more active higher-frequency retail investors as well as larger passive ones which require fewer trades and lower commission expenses.