“The United States stock market looks very expensive right now. The CAPE ratio, a stock-price measure I helped develop — is hovering at a worrisome level…. above 25, a level that has been surpassed since 1881 in only three previous periods: the years clustered around 1929, 1999 and 2007. Major market drops followed those peaks.” -Robert J. Shiller, Nobel Prize-Winning Economist and Author of “Irrational Exuberance”

Popular response: the CAPE ratio is flawed and valuations don’t matter anyway; stocks are only worth what someone else is willing to pay.

“George Soros Just Made A Huge Bet That US Stocks Might Fall” –Business Insider

Popular response: he’s not betting stocks are going lower; it’s just a hedge against his long exposure.

“Yellen’s [recent] comments suggest, and I agree, that we are in an asset bubble.” –Carl Icahn

Popular response: 1999 was a bubble; this isn’t a bubble.

Rationalize. Rationalize. Rationalize.

Time and time again investors flat out deny what’s staring them dead in the face: stocks are extremely overvalued and at risk of yet another major decline. The last time I can remember investors rationalizing bearish data points as much as they are today was during the height of the internet bubble. ‘P/E’s don’t matter any more; it’s a new economy,’ was the battle cry back then. Today it’s, ‘it’s impossible to value a stock or the market,’ and ‘this is nothing like the internet bubble.’

To an outsider, someone who has nothing to do with the markets, the logical fallacies must be painfully obvious.

Criticizing the CAPE is a classic straw man. Tobin’s Q Ratio, a valuation measure used by the Fed, along with Buffett’s favorite yardstick, total market capitazliation relative to GNP, both confirm that the stock market is extremely overvalued, using three totally unrelated valuation methods. Another thing the bulls fail to mention is that these three measures are highly correlated to future 10-year returns for stocks and suggest the potential risk at this point is far greater than the potential reward. These are just facts!

And comparing today’s market to the internet bubble is a clear Red Herring. Just because today’s market is not exactly like that of 1999 doesn’t prove that we’re not in a bubble today. In fact, it’s totally irrelevant. Today’s market should be judged on the full measure of the data available to us. And just like Shiller says, there have only been a very rare number of times stocks have been this overvalued: 1929, 1999 and 2007. These are just facts!

Then we get into the Ad Hominem attacks. ‘Shiller’s just a professor; he’s not a market practitioner so he doesn’t know what he’s talking about’ or ‘Soros and Icahn are just like all the other hedge fund big wigs out there using the media to make short-term profits; you can’t read anything into what they do or say,’ not to mention the attacks on John Hussman that completely ignore the merits of his research on its own.

I get it. It’s extremely difficult to listen to reason when the madness of the crowd is simply deafening. At the end of the day, though, it’s all just a huge sign that investors are desperate to believe, to keep hope alive that 30%-per-year profits can happen again this year and the next.

So if you didn’t know what a mania was before now, just take a look at the financial blogs and social media sites. The rationalization is everywhere. And it may be the best indicator of all that we are, indeed, in the midst of yet another bubble.