In the context of investment, what does a "variable" typically reference?

In the context of investment, a "variable" typically refers to a separate account. A separate account is an investment vehicle that allows an investor to have their funds allocated in a way that can fluctuate based on the performance of the underlying investments. This contrasts with fixed income investments or guaranteed rates, which do not change in value and provide a steady return. Separate accounts often allow for greater investment flexibility and can be used in a variety of products such as variable life insurance or variable annuities, where the return is dependent on the investment performance of the account, making them inherently "variable."

Other options like fixed income investments and guaranteed rates imply stability and predictability, while a cumulative account may refer to interest accumulation or value growth over time, neither of which captures the essence of variability in investment performance as effectively as a separate account does.