Rule No. 9: Defend Some Stocks, Not All

Editor's note: Jim Cramer's new book, Real Money: Sane Investing in an Insane World, is available in selected bookstores now. As a special bonus to RealMoney readers, we will be running Cramer's "Twenty-Five Rules of Investing." For more about the new book and to order it, click here. Today, we present Cramer's ninth rule of investing. To read about his first rule, click here; for his second, click here; for his third, click here; for his fourth, click here; for his fifth, click here; for his sixth, click here; for his seventh, click here; for his eighth, click here.

---

When the markets are hard and unrelenting, as this one has become this year, it's important to remember an adage that's well-suited for a battlefield plan but is just as valuable for a portfolio plan: ...