This column was originally published on RealMoney on July 19 at 10:58 a.m. EDT. It's being republished as a bonus for TheStreet.com readers. For more information about subscribing to RealMoney, please click here.

Count the wrong assumptions on a daily basis. Altria ( MO) reports an outstanding quarter, after a series of disappointments, but the stock goes down yesterday, and people say it is a bad quarter.

Intel ( INTC) disappoints. Why? Because it can't charge enough for its microprocessors because of a price war, but it says that the demand, particularly for notebooks, is incredibly strong.

So what happens? Hewlett-Packard ( HPQ), which is the notebook king and a huge supplier of microprocessors, goes down!

American Standard ( ASD) finalizes the break-up plans -- they look great -- management is energized to create value, and one of the divisions, kitchens and baths, slips, and it gets hammered. Who the heck cares? The company won't even exist as it is next quarter.

Clearwire opens in the $20s, it is loved, it goes to $16, it is hated, and then the technology gains adherent after adherent because Craig McCaw is such a winner, so it doubles.

So many people take their cues from a wacky stock market and the short-term price moves, rather than from their own counsel. Drives me nuts. For two weeks I had to hear about how something was wrong with International Game Technology ( IGT). Nope. There was nothing wrong, just a bunch of stupid, fearful sellers operating at the same time.

I am telling you that everyone who is betting against NYX ( NYX) because it will buy Nymex ( NMX) and it will pay too much will be dead wrong, and that stock will be proven to be ridiculously undervalued.

Take your cue not from the price movements but from the conviction you have. If you don't have conviction, don't own.

How many people in Stockpickr.com are going to ask me if I told them to sell Goldman Sachs ( GS). No, I am saying that the stock market is going to misvalue GS for a while, and if you can't handle the pain, get out.

The stock market misvalues all of the time. It clearly misvalued infrastructure last year when Foster Wheeler ( FWLT) was at $33. It misvalued the homebuilders when they were wild high just a year and a half ago.

That's why fundamental work matters. Because no matter what you do, if you don't rely on fundamentals -- if you rely on charting, like the young man who wrote in Stockpickr that Goldman had reached a double bottom at $223 and that now was time to buy, if you rely on random stock market moves that are caused by sellers who don't know much -- I am guaranteeing you will lose money.

Guaranteeing! How many people are willing to do that for you? But I will make it a lifetime guarantee -- that's how unworried I am about your taking cues from the stock market to lose big money.

Random musings: Chumps? That's what the market is saying about Eddie Lampert and Sears ( S) and the people at UnitedHealth ( UNH) who keep buying back their stock. People think these guys are idiots. Last I looked, they weren't. But our friends in the market say they are. ... The bears are already telling you why good numbers from Bank of America ( BAC), Washington Mutual ( WM) and Merrill ( MER) are all made up and wrong. That stuff's not going away anytime soon, so don't bet that way.

At the time of publication, Cramer was long Goldman Sachs, International Game Technology, NYX, Sears, UnitedHealth, Hewlett-Packard and Altria.

Jim Cramer is a director and co-founder of TheStreet.com. He contributes daily market commentary for TheStreet.com's sites and serves as an adviser to the company's CEO. Outside contributing columnists for TheStreet.com and RealMoney.com, including Cramer, may, from time to time, write about stocks in which they have a position. In such cases, appropriate disclosure is made. To see his personal portfolio and find out what trades Cramer will make before he makes them, sign up for Action Alerts PLUS. Watch Cramer on "Mad Money" weeknights on CNBC. Click here to order Cramer's latest book, "Mad Money: Watch TV, Get Rich," click here to order his book, "Real Money: Sane Investing in an Insane World," click here to get his second book, "You Got Screwed!" and click here to order Cramer's autobiography, "Confessions of a Street Addict." While he cannot provide personalized investment advice or recommendations, he invites you to send comments on his column by clicking here.

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