Latest NPR Planet Money podcast episode was about bubbles, they interviewed a university professor that was running experiments on his students. They had a fake stock market with only one stock on it that would have a random dividend of either $0 or $2, so $1 on average. Students were given money to invest in the stock market. Running this experiment apparently over multiple courses, even in this small market there would be bubbles.

He brought up one such bubble in a lecture in front of the students, explaining to them that their investment made no sense considering the average dividend. He expected this explanation to crush the bubble since now everyone was aware of it. What happened instead was students going "wow, a bubble, I must get in on it!" and the stock just going even higher.

Shouldn't you be elated? If this is a repeat, just do what you wished you had done the first time around and Step 3. Profit!

People play roulette even though it's easy to calculate the casino's advantage.

Why is this disappointing?

If the IPO window's open, it's time to try and climb through it! I couldn't be more excited.

The way I see it is: if you have to ask if you're in a speculative bubble, odds are you're in a speculative bubble.