Marvin Goodfriend, an economics professor at Carnegie Mellon University, says that if the Federal Reserve were really committed to price stability, retirees would be in a much better situation today. Brian Wieser, an analyst at Pivotal Research, says Snap has created a successful product but the bigger question is whether Snap can increase revenue. David Kirkpatrick, CEO and founder of Techonomy Media, says Snap isn't like Twitter because it's got a real business. Finally, USB Securities' Julian Emanuel says enthusiasm isn't as high as it was in 1999 or 2000, suggesting valuations may still move higher.