There are some common ways that investors use ETFs, and these include investments in commodities or international stocks, and also using ETFs for hedging. Investing in commodities is easier with ETFs. Commodities are raw materials that are interchangeable and tradable. By this, I mean that a commodity such as a barrel of oil can be exchanged for another barrel of oil, whereas a handmade tailored wedding dress cannot be swapped out for another wedding dress. Commodities include energy, such as oil and natural gas; precious metals, such as gold and silver; and agriculture, such as corn and even cows. If you wanted to bet that the price of gold will increase, you could buy gold from a jewelry store and hide it under your bed, then if the price of gold increased as you expected, you could sell it for a profit.