So how can you ensure you're not harmed in future by slick rhetoric? First, by forcing yourself to admit, when the first signs of fraud appear, that you have been duped. Don't let your pride stand in the way. Get out. This way, you avoid staying on to the grim end with future Nortels.
Second, whenever you see a talking head pushing a stock or a fashionable disaster on TV, ask yourself: “Who pays him?” Everyone in the market is talking up his book, yet once a mania starts, everyone has the same book, and so they all push the same thing higher until it all unravels.