Speculative Bubble

See: Speculation. See: Bubble. See: Tech Bubble.

So what's the diff between a bubble and just a hot market or a high-growth new industry buzz?

Well, a bubble is about ludicrous optimism. Thin, fragile walls. No sense for downside risk. Crazy valuations that make no sense. Weekend football announcers giving advice on stock picks. When that happens, "sell, Mortimer, sell," and run for the hills (with a mattress stuffed with cash).