Establishing an appropriate asset mix is a dynamic process, and it plays a key role in determining your portfolio's overall risk and return. As such, your portfolio's asset mix should reflect your goals at any point in time. There are a few different strategies of establishing asset allocations, and here we outline some of them and examine their basic management approaches.

Strategic Asset Allocation
Strategic asset allocation is a method that establishes and adheres to what is a 'base policy mix'. This is a proportional combination of assets based on expected rates of return for each asset class. For example, if stocks have historically returned 10% per year and bonds have returned 5% per year, a mix of 50% stocks and 50% bonds would be expected to return 7.5% per year.

Constant-Weighting Asset Allocation
Strategic asset allocation generally implies a buy-and-hold strategy, even as the shift in the values of assets cause a drift from the initially established policy mix. For this reason, you may choose to adopt a constant-weighting approach to asset allocation. With this approach, you continually rebalance your portfolio. For example, if one asset were declining in value, you would purchase more of that asset, and if that asset value should increase, you would sell it.

There are no hard-and-fast rules for the timing of portfolio rebalancing under strategic or constant-weighting asset allocation. However, a common rule of thumb is that the portfolio should be rebalanced to its original mix when any given asset class moves more than 5% from its original value.

Tactical Asset Allocation
Over the long run, a strategic asset allocation strategy may seem relatively rigid. Therefore, you may find it necessary to occasionally engage in short-term, tactical deviations from the mix in order to capitalize on unusual or exceptional investment opportunities. This flexibility adds a component of market timing to the portfolio, allowing you to participate in economic conditions that are more favorable for one asset class than for others.

Tactical asset allocation can be described as a moderately active strategy, since the overall strategic asset mix is returned to when desired short-term profits are achieved. This strategy demands some discipline, as you must first be able to recognize when short-term opportunities have run their course, and then rebalance the portfolio to the long-term asset position.

Dynamic Asset Allocation
Another active asset allocation strategy is dynamic asset allocation, with which you constantly adjust the mix of assets as markets rise and fall and the economy strengthens and weakens. With this strategy you sell assets that are declining and purchase assets that are increasing, making dynamic asset allocation the polar opposite of a constant-weighting strategy. For example, if the stock market is showing weakness, you sell stocks in anticipation of further decreases, and if the market is strong, you purchase stocks in anticipation of continued market gains.