This post appeared earlier today on RealMoney. Click here for a free trial, and enjoy incisive commentary all day, every day.

Great to see Warren Buffett buying here. Fabulous. He has a lot of firepower. He is right to buy American. And I want to go with him, except, he's been buying for awhile, and, more important, he can be down 20% to 30% and it doesn't matter.

Buffett emphasizes over and over again that he can't time the market. Over and over again, he makes the point that he is in it for the long term.

So let's play it out. Buffett's like the casino. He's the house. He can take an endless beating. Endless. He is adamant that he can't predict the short term.

So, let's do the math. Let's say he is as wrong in these new buys as he was in his General Electric ( GE) buy a few weeks ago. If you use, for the sake of argument, the allegedly controversial call I made when the Dow was at 10,000 that you need to take as much money out of the market as you may need for a big purchase in the next five years, you will need to gain 37% in your stocks to get back to even. Thirty-seven percent.

Do you think that you will be able to make that back? Maybe if you are the house, like Buffett, maybe if you have a long-term time frame.

But that was never my point. My point was that, if you need that money in the short term, it is better not to have it in the market.

Most people invest in the stock market for an augmentation of their paycheck so that they can make it easier for a big purchase, a car, a house, tuition, retirement.

If you could sidestep a decline that would require your portfolio to rise 37% to get back to even, is that prudent or is that reckless? If you know that you have to put your kid through college with a 529 plan but it will require a major comeback to make it so you have the money, don't you think you need the five years to get back there? That's a big move, especially considering that the S&P 500 has made you nothing over the past 10 years.

This is simple arithmetic.

These buys are of absolutely no consequence to him whatsoever. He may very well make fortunes on his buys. And he has waited until stocks are down.

But are you Warren Buffett? Are you as rich as he is that you don't need to worry about those big purchases? If you are, I say bombs away. Go with him.

If you are not, consider that, if you followed him with GE and then followed him today with this New York Times picks and those prices fell as much as GE did, you would be in a real jam.

Look, the easiest thing to do at all times is to say, "Stay the course." It's a natural. It is a terrific, easy strategy that can never be refuted ever because at no point are you ever wrong.

Ever.

I repeat, Buffett is the house. He is the casino. He can have whole months, even years, where he can get clobbered by the drop.

Can you?

Random musings: I think the futures should not have been down big this morning. That smelled like another S&P liquidation from still one more hedge fund. I continue to believe that tech leads us. Qualcomm ( QCOM), which I own for Action Alerts PLUS, should trade with Nokia ( NOK), which put on a pretty good face.

At the time of publication, Cramer was long General Electric and Qualcomm.

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. To order Cramer's newest book -- "Jim Cramer's Stay Mad for Life: Get Rich, Stay Rich (Make Your Kids Even Richer)," click here. Click here to order "Mad Money: Watch TV, Get Rich," click here to order "Real Money: Sane Investing in an Insane World," click here to get "You Got Screwed!" and click here for Cramer's autobiography, "Confessions of a Street Addict." While he cannot provide personalized investment advice or recommendations, he appreciates your feedback and invites you to send comments by clicking here.

TheStreet.com has a revenue-sharing relationship with Amazon.com under which it receives a portion of the revenue from Amazon.com purchases by customers directed there from TheStreet.com.

More from Opinion

Throwback Thursday: Intel Edition

Throwback Thursday: Intel Edition

Intel's Next CEO Should Try Harder to Protect Its Flanks Against AMD and Others

Intel's Next CEO Should Try Harder to Protect Its Flanks Against AMD and Others

3 Warren Buffett Stock Picks That Could Be Perfect for Your Retirement Portfolio

3 Warren Buffett Stock Picks That Could Be Perfect for Your Retirement Portfolio

Wednesday Wrap-Up: GE and Facebook

Wednesday Wrap-Up: GE and Facebook

PayPal Strikes Again, Facebook, and AT&T -- 3 Tech Stories You Must Know

PayPal Strikes Again, Facebook, and AT&T -- 3 Tech Stories You Must Know