Bursting the Bubble Tulips were the first, but they won’t be the last. What forms a “bubble” and what causes them to burst? Share | Related Content When Markets React When markets shift, experienced investors stick to their strategy. Rebalancing Your Portfolio Over time, different investments' performances can shift a portfolio’s intent and risk profile. Rebalancing may be critical. 5 Smart Investing Principles Principles that can help create a portfolio designed to pursue investment goals.