While discussing tips on when to buy and when to sell in the stock market, Jim Cramer said on his

"RealMoney" radio show Monday that the common principal on Wall Street of buy and hold is "gibberish and brainwash."

"You have to buy and do homework -- that's the tactic," he said. "When you do homework, you'll get out before things get bad."

Buy weakness, sell strength, Cramer iterated.

When Cramer said that when he looks at a stock, he doesn't know how high or low it will go and that "no one should be that arrogant."

Remember not to buy all at once, but in stages, he said. Once a stock goes lower, buy a little more, and when it goes high, sell a little on strength.

People who fail to do their homework will ride stocks to zero, but Cramer said that when you buy and have a gain, it's OK to take something off the table. Similarly, "selling is important to your arsenal," he said.

"Your first loss is your best loss," he said. "When you find something wrong with a company, it's OK to sell."

To see the most recent edition of The RealMoney Radio Recap in its entirety, please click here. This recap is published every day around 3 p.m. ET.

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