A lockup period for hedge funds restricts a multi-period investor's ability to rebalance his portfolio and has non-trivial effects on the allocation decision and portfolio efficiency. Investors compensate for a hedge fund lockup period by making adjustments to their equity and bond holdings....

We develop a model of portfolio choice capable of nesting the views of Keynes, advocating concentration in a few familiar assets, and Markowitz, advocating diversification across all available assets. In the model, the return distributions of risky assets are ambiguous, and investors are averse...