The most important investing rule

Investors would be best left to focus on the basics, and stick to what they can possibly know. It’s knowable that Warren Buffett’s company, Berkshire Hathawa (BRKA)gets special access to investments. That gives him an advantage. It’s knowable that Costc (COST)sells more product per square foot and turns its inventory over faster than virtually all of its competitors. That gives it an advantage. It’s knowable that RadioShac’s (RSH)competitors sell the same stuff at lower prices. That puts it at a massive disadvantage.

The above concepts are simple ideas that have underlied investment profits to the tune of billions of dollars. Simple ideas won’t earn you a Nobel Prize, but they can earn you fantastic results in the stock market.

2. Selena Maranjian: The most important rule of investing is to learn, learn, learn… and keep learning.

Morningstar: © 2015 Morningstar, Inc. All Rights Reserved.

Factset: FactSet Research Systems Inc. 2015. All rights reserved.

Chicago Mercantile Association: Certain market data is the property of Chicago Mercantile Exchange Inc. and its licensors. All rights reserved.

CNN Money