“If it’s obvious, it’s obviously wrong” (or “the obvious is obviously wrong”) is a popular stock market saying. If something is obvious to everyone (such as a bullish or a bearish market), then that is usually factored into the market prices. The contrarian position is usually not factored in.
 
Financial author Joseph E. Granville (1923-2013) wrote in A Strategy of Daily Stock Market Timing for Maximum Profit (1960):
 
“Remember, if it’s obvious to the public it’s obviously wrong.”
 
     
Wikipedia: Joseph Granville
Joseph Ensign Granville (August 20, 1923 – September 7, 2013), often called Joe Granville, was a financial writer and investment speaker. He popularized the use of “on balance volume”, a technique of technical analysis that attempts to predict future prices of stocks, commodities, and other financial assets traded on financial markets for which historical price and volume information is available.
 
Granville is probably best known for his bearish market calls during the 1970s, 1980s, and 1990s, when he claimed that the stock market was headed for imminent collapse. His overall track record, according to the Hulbert Financial Digest, is very poor.
 
Google Books
A Strategy of Daily Stock Market Timing for Maximum Profit
By Joseph E. Granville
Englewood Cliffs, NJ: Prentice-Hall
1960
Pg. 212:
Remember, if it’s obvious to the public it’s obviously wrong. Majority opinion can be moulded but the technical indicators are beyond the reach of the majority opinion moulders. There are too many of them.
 
15 December 1960, Boston (MA) Traveler,“You And Your Money: Here’s The Way Technician Looks At Stock Buying” by Dick Miller, pg. 51, col. 6:
Like most professional stock traders, he (Joseph E. Granville—ed.) is skeptical of public opinion. “If it’s obvious to the public, it’s obviously wrong.” He points out that when everybody’s bullish, stocks may suddenly start to sell off.
   
Google Books
The Stock Market Teacher:
Technical Analysis for the Post-Crash Period
By Joseph E. Granville
Kansas City, MO: Granville Market Letter
1988
Pg. 59:
If it is obvious, it is obviously wrong.
Pg. 123:
“If it is obvious, it is obviously wrong.”
 
Google Books
The Psychology of Finance
By Lars Tvede
Oxford: Oxford University Press
1990
Pg. 164:
This situation is, as Joseph Granville expressed it in A Strategy for Daily Stock Market Timing from 1960: “When it’s obvious to the public, it’s obviously wrong.”
 
Google Books
How to Invest in the Market:
The ‘90s Guide to Wall Street
By Dan G. Stone
New York, NY: Madison Pub. Associates
1990
Pg. 233:
At the same time, while other investors focus on the apparent and the irrelevant, you should remember that “if it’s obvious, it’s obviously wrong.”
 
Google Books
The Streetsmart Guide to Timing the Stock Market:
When to Buy, Sell, and Sell Short
By Colin Alexander
New York, NY: McGraw-Hill
1999
Pg. 379:
Joe Granville has a saying worth remembering: “If it’s obvious, it’s obviously wrong.” What that often means is that if an opportunity is obvious, then everyone wanting to exploit the apparent opportunity may already have done so.
 
Google Books
The Complete Idiot’s Guide to Market Timing
By Scott Barrie
Indianapolis, IN: Alpha
2003
Pg. 71:
This is because most people operate on conventional wisdom. To quote another old market axiom, “If it’s obvious, it’s obviously wrong” is the battle cry of the contrarian.
     
The Market Oracle
Stock Market Gloom and Doom - “Granville’s Golden Rule” Versus Conventional Wisdom
Jan 26, 2008 - 01:02 AM GMT
By: Clif_Droke
(...)
The market is now testing and will soon provide an answer as to the veracity of that old Joe Granville saying, “The obvious is obviously wrong.”
 
Raging Bull
#1741673 canuck2004 2011-09-10 14:53
To paraphrase Joe Granville from his 1960 book, “If it’s obvious to everyone, it’s obviously wrong.”
   
Google Books
All About Day Trading:
The Easy Way to Get Started
By Jacob Bernstein
New York, NY: McGraw-Hill
2013
Pg. 210:
I remembered fondly and frequently the words of Joe Granville, who had told me so many times that if it’s obvious, it’s obviously wrong.
 
Business Insider
One Trader’s 21 Favorite Quotes About Markets And Investing
SHANE OLIVER, AMP CAPITAL, BUSINESS INSIDER AUSTRALIA APR. 30, 2014, 5:32 AM
(...)
“If it’s obvious, it’s obviously wrong.” Joe Granville
This doesn’t apply to everything (eg if it is obviously sunny outside according to the usual definition, then it is!), but investing can be perverse. When everyone is saying “it’s obvious that the recession will continue” or “it’s impossible to see a recession as things are obviously good” then maybe the crowd is already on board and the cycle will soon turn.