NEW YORK (TheStreet) -- Snapchat is reportedly planning to raise money at a stratospheric valuation of $19 billion, while Pinterest is looking for an $11 billion valuation. The Nasdaq (QQQ - Get Report) is close to an all-time high. Is this 1998 to 2000 all over again?

For comparison, here's a chart of some of the most richly-valued start-ups today, followed by some of the biggest flameouts of the 1998 to 2000 dot-com bubble.

Few analysts believe valuations have gotten as disconnected from reality as they were in the previous era, and many of these failed companies lacked even a plausible business model compared to today's companies.

But the valuations achieved by some of the previous era's companies are still worth looking at as a cautionary tale.