Asset bubbles are easy enough to define, but not so simple to identify. WSJ’s Gunjan Banerji explains what bubbles are exactly, how they form and what happens when they burst. Illustration: Jacob Reynolds for The Wall Street Journal More from the Wall Street Journal: Visit WSJ.com: http://www.wsj.com Visit the WSJ Video Center: https://wsj.com/video On Facebook: https://www.facebook.com/pg/wsj/videos/ On Twitter: https://twitter.com/WSJ On Snapchat: https://on.wsj.com/2ratjSM #Gamestop #Tulips #WSJ