This paper looks at how unpredictable changes in volatility affect the best investment choices. Three different models are used to study this: an extended Stein/Stein model, the Heston Model, and an extended Heston Model with a constant elasticity variance (CEV) process. The researchers found that the Heston model is the simplest and most favored. All three models show that having a mix of investments over time is important, along with a static portfolio. The specific details of the investment strategies vary between the models. The researchers also discovered that the investment strategies are influenced by the CEV parameter.