It might be an understatement to say that investors are pumped up about social networks and other tech companies. And the numbers are eye-popping. Twitter: valued at $11 billion. Pinterest? $4 billion. And the list goes on.

If all of this makes you feel a bit of queasiness and déjà vu, you’re not alone. Lots of people are talking about the dot-com bubble of the late 90s — and, boy, did that bubble pop. Should we be nervous?

Marketplace Host Ben Johnson speaks with Lindsey Turrentine of CNET.