Forget the dot-com boom with its "irrational exuberance" and the real estate bubble that was supposed to be invincible: Current market sentiment eclipses all of that.
In fact, bullishness has never been this high going all the way back to 1987.
That's through three rousing bull markets, a couple of crashes, the "Great Moderation" of the 1990s and all sorts of other history-making events. A market that was supposed to flounder this year under a new president instead has taken off, and investors are pumped.
Bullishness is at 63.1 percent of market professionals responding to the latest Investors Intelligence survey. That's the highest level since the year of the infamous "Black Monday" Oct. 19, 1987, crash that sent the U.S. market down nearly 23 percent in one day.
All the optimism comes with the market setting a succession of new highs, including trading Wednesday that pushed major averages up more than 1 percent across the board.
"You can totally understand why this is where it is considering the market action," said Nick Colas, chief market strategist at Convergex. "What's hard about interpreting it against 30 years of history is you have a very unusual period in economic and political history now, so you have to throw out the usual rulebook."