People are more interested in the concept of a "stock bubble" than they've been at any time since the housing bubble collapsed. But ironically, that very concern could be what prevents another bubble from forming anytime soon.
According to Google Trends, worldwide search interest in the term "stock bubble" is higher in November 2013 than in any month since October 2008. The rise in interest is even more pronounced in the United States, where in data going back to 2004, the volume of searches for the term is the highest it's ever been (with the exception of the bubble-period around November 2007.)
Paradoxically, many market participants say this should actually calm those who fret that equities are currently in a bubble.
"That means, conclusively, that there is no stock bubble," Jim Iuorio of TJM Institutional Services told CNBC.com. "It means that people aren't caught up in the hysteria of being deluded that there is no bubble, which is the only way that a bubble can exist."
Mark Dow, a former hedge fund manager who writes at the Behavioral Macro Blog, diagnoses investors with a bad case of "disaster myopia."
"If you went through an earthquake, or were mugged, or whatever traumatic event it might be, you overestimate the probability of that event occurring again," Dow said. "It's because we just went through a bubble that everyone's looking for them. Generals always fight the last war, and firemen fight the last fire."
Dow similarly believes that the tremendous deal of concern about a bubble will "probably prevent it," at least for a little while.
"It's never obvious, by definition, or you wouldn't get the bubble," he said.
(Read more: 3 technical reasons to be nervous about stocks)