"We are not in a regular market," Jim Cramer told "RealMoney" radio show listeners Friday. "This is a market that goes up for periods and down for periods ... and this needs new rules." So, Cramer gave listeners his "10 Commandments of Trading" that he used to navigate the choppy waters of the 1990s stock markets. Trading is different from investing, he said. Trading means you're going to take some off the table. It's buying and selling. Investing means you're in a stock for a longer period of time. And you have to decide the day you buy whether it's for a trade or an investment, Cramer said. A trade is a stock that you buy because you believe that some catalyst will push the stock higher, allowing you to sell and lock in a gain. This lead Cramer to his first commandment. Commandment No. 1: Never turn a trade into an investment. If you're buying for a trade, and your specific catalyst doesn't occur, or if it happens and the stock doesn't budge in a few days -- get out, he said. Don't decide to hold onto the stock for an investment. Nothing about the company has changed, so you shouldn't change your mind and hold onto the stock. Commandment No. 2: Your first loss is your best loss. Cramer said that if your trade goes down, you have a problem, and you want to get out soon when the decline still amounts to a short period of time or a small dollar amount. Cut your losses quickly and get over them quickly, he said, because the losses to come will be at lower levels and at a bigger cost. "People can feel when a trade is going awry, but because of ego, because of pigheadedness, they don't want to hear the thunder," he said. Then they must panic out at lower levels.