There are so many markets, exchanges, and contracts that you can trade. It becomes an overwhelming task to pick and choose just the right markets and just the right exchanges to interact with. At the same time, the various markets fall into several broad categories: stocks, indexes, interest rates, currencies, agriculture, softs, precious metals, industrial metals, energy, and meats. There are also several exotic categories such as the climate and oils. In this article the goal is to narrow down the universe of markets and to make examples of just a handful. The markets that are represented are meant both to be broad strokes of a category and to reflect the interrelationship that this market has with various other factors in the economy.By no means is this done to suggest that you trade these markets exclusively or to teach you to trade these markets to riches. They are meant as examples to assist you in selecting your markets to trade. My book ‘Winning the Trading Game’ (John Wiley & Sons, 2008) outlines how to select markets for your own risk, reward, and volatility levels. Reading that book will do a better job of helping you determine what is right for you instead of blindly following the markets that are outlined in this article. The goal here is to see you become a trader who can nimbly look at a market and construct a trading approach around it, regardless of what it is.That being said, five markets were chosen for their robustness, current international importance, and the fact that they are traded across multiple contract types. While not the only markets to meet these criteria, they are the easiest to recognize among a slew of other contracts. The examples in this article revolve around the S&P 500, gold, crude oil, euro, and corn. Many other contracts are also relevant in today’s trading environment, including U.S. Treasury bonds, the CAC 40, DAX, soybeans, Japanese yen, silver, and the eurodollar.The funny thing about trading is that you do not need to be in a market to benefit from the correlative effects of that market’s activity. For example, when you short the euro in futures, you are essentially buying the dollar as well; therefore, you do not need to be also be short the yen, for you would be exposing yourself to the same long dollar risk. If you are buying gold, you do not need to also buy silver and double expose yourself to a precious metal long side bias. Or if you are long corn, it is rare that you need to also participate in all of the grain complexes, wheat-soybean. As always, choose the markets you are most comfortable with.S&P 500The S&P 500 is one of the most widely tracked indexes. It contains stocks of 500 large-cap corporations. It is a mixture of stocks that trade on the NYSE Euronext and NASDAQ. The success of the S&P 500’s ability to gauge the U.S. economy is rivaled only by the Dow Jones Industrial Average. Over 20 years ago the CME launched the first-ever stock-index futures on the S&P 500.The S&P 500 futures contract was meant to fill a need for money managers and investors with large stock portfolios seeking to minimize their exposure to risk. In 1998 a smaller version of the S&P 500 futures contract was introduced, the E-mini S&P 500. One-fifth of the size of the full-size S&P 500 futures contract, the E-mini has gained in volume and liquidity over the years. In fact, it is the preferred contract of many institutional traders because of its electronic execution. As of this writing the notional daily value of the traded E-mini S&P 500 is over $140 billion. This is a gross exaggeration of the value of the actual shares traded on a daily basis.The S&P 500 futures contract plays a significant role in determining the opening of price of the actual index on the NYSE. This is due in large part to the fact that the E-mini S&P 500 futures contract trades 23.5 hours per day five days a week.GoldMetals come in two general categories, precious and nonprecious. The precious metals are gold, silver, platinum, and palladium. They tend to be prized for their jewelry qualities even though they also have industrial and financial applications as well. The two precious metals that sit at the forefront of all precious metals trading are gold and silver. From India to New York, gold’s long precious metals history has given it a seat on several commodities exchanges and has helped it to develop a robust OTC market in the past decade.With the average mining expense of gold at $238 per ounce, it is a wonder that the price of gold stagnated in the $300 per ounce range for almost a decade. Couple the high cost of mining with the limited supply of gold worldwide, and gold has the potential to continue on a significant bull run. As of this writing the price of gold has exceeded $950 per ounce. The last previous time it exceeded $800 was January 21, 1980; adjusted for inflation that would be approximately $2,398.21.Crude OilThe finding and drilling of oil has changed the world as we know it for the past 100 years. Crude oil’s impact on the environment, on economies around the world, and on substitute goods will continue to affect the world for another century to come. Energy trading became a significant part of futures in 1978. Energy futures and OTC contracts cover a wide array of energy products from crude oil to electricity, with crude oil leading the pack. OTC energy trading can be directly attributed to the Commodities Futures Modernization Act of 2000. With the liberalization of the futures rules, energy contracts have become quite popular to trade.The crude oil market has three large players: Saudi Arabia, Russia, and the United States. With over five thousand varieties of crude oil available, it is no surprise that OTC oil futures have played a significant role in reshaping the commodities landscape. The most commonly sought-after crude oil, sweet crude, is also becoming the most difficult to come by. Couple that with limited access to the most touted crude oil alternative, natural gas, and we have an energy market that will be overheated for years to come.EuroThe OTC foreign exchange market is a several trillion dollars a day industry. Quite literally, more money is moved daily in the forex market than in the U.S. equity market and all of the futures exchanges combined. This market is raw capitalism at work. With a six-day, 24-hour time schedule, it is one of the most exciting places around to put your money, retail or institutional.Fueling a significant portion of this growth has been the creation of one of the most important currencies in the twenty-first century, the euro. Consolidating the economies of the 15 countries that are members of the European Union, the euro was launched in January 2002. Affecting the lives of over 500 million people, the euro has surpassed the dollar in terms of use and value.CornCorn is one of the most versatile commodities in the world. Whether used for livestock feed or whiskey, sweetener or fuel, corn is a staple in the lives of people around the globe. With over 600 million metric tons being produced worldwide, it is a valuable part of the economy in a number of countries. The United States alone accounted for 280 million metric tons. Couple the agricultural uses of corn with its potential to be used as a fuel additive or fuel alternative to gas, and corn production may be seen as being more in its infant stage. With China currently producing only 131 million metric tons and Brazil at 35 million metric tons, these two countries alone have the ability to expand their corn production, particularly to meet demands of the burgeoning economies.