Crystallization

Crystallization is a strategy to help reduce capital gains taxes.

An investor sells a security to achieve a capital loss, perhaps to offset capital gains on the sale of another security. But since the investor believes that the stock which was sold at a loss still has a lot of future potential, he or she buys it back again.

However, the tax man frowneth upon this technique, so you will need to wait at least 30 days before you buy the same stock back.