If ETFs had a Mount Rushmore, QQQ (aka 'The Qs') would definitely be on it. This $72 billion legend of an ETF just turned 20 years old and is now the second most traded security in the world. But how much do investors really know about it?  On this week’s Trillions Carolina Wilson of Bloomberg News sets out to the Midwest with microphone in hand to talk to those who built the original index and the ETF as well as tracked its changes over the years. Her journey lead to some interesting discoveries as well as a trip to the Chicago zoo, where she actually got a lion to roar. See omnystudio.com/listener for privacy information.