STOCK: A magical piece of paper that is worth $37.50 until the moment you buy it. It will then be worth $8.95.
BOND: What you had with your spouse until you pawned his/her golf clubs to invest in Amazon.com.
BROKER: The person you trust to help you make major financial decisions. Please note the first five letters of this word spell "Broke."
BEAR: What your trade account and wallet will be when you take a flyer on that hot stock tip your secretary gave you.
BULL: What your broker uses to explain why your mutual funds tanked during the last quarter.
MARGIN: Where you scribble the latest quotes when you're supposed to be listening to your manager's presentation.
SHORT POSITION: A type of trade where, in theory, a person sells stocks he doesn't actually own. Since this also only ever works in theory, a short position is what a person usually ends up being in. (i.e. "The rent, sir? Ha. Ha. Ha. Well, I'm a little short this month.")
COMMISSION: The only reliable way to wake money on the stock market, which is why your broker charges you one.
YAK: What you do into a pail when you discover your stocks have plunged and your broker is making a margin call.
