The market could “go either way”

“Sam’s fatal flaw...is that he had a preconceived idea of where the market would go...when conditions changed...Sam refused to accept the new evidence...Instead, Sam began to search for shreds of evidence to support his bearish case. This is a very common trait of stock market investors. Psychologists would call it ‘selective perception’. One sees only what one wants to see. Unfortunately, in the stock market, there is always some bearish evidence and some bullish evidence. You never have difficulties unearthing clues to back your viewpoint...I could argue that a year after I had turned bullish the market was higher. I could argue that I was not wrong, just ‘early’. I could stubbornly insist that I was right and the market was wrong...The fact is, I was just plain wrong, I knew deep in my bones I was wrong, but my ego got the best of me…” - Martin Zweig in Winning on Wall Street