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 | Have A Question About This Topic? Name Email Address Question Thank you! Oops! Related Content The A, B, C, & D of Medicare Learn about all the parts of Medicare with this informative and enjoyable article. Mutual Funds vs. ETFs Exchange-traded funds have some things in common with mutual funds, but there are differences, too. Understanding Extended Care Understanding the types of extended care services—and what those services could cost—may be critical.