It has been consistently demonstrated that your investment returns aren’t so much a function of what stocks your invested in, but what sectors/asset classes your invested in. In the dot com boom, it didn’t matter what dot com stock you invested in, if you were invested in dot com companies, you probably did alright. During the dot com bust, it wasn’t just a couple select companies that went down, it was just about all of them. Because of this tendency for similar stocks to move together, it is much more productive to be able to simply buy ” or short – a type of stock, then try and nail the exact right company. But how can you gain exposure to a sector without taking unnecessary risk based on the company?