"Buy low, sell high" is the mantra of the stock market. Perhaps the most extreme example of this is arbitrage, the act of buying and selling goods simultaneously in different markets to gain an immediate profit. Impressive, but tricky.
Although the meaning of the word arbitrage as used today is relatively new, dating back to the late 19th Century, the word itself can be traced back to the Latin arbitrārī, with the meaning "to regulate." In English, arbitrage first meant "using personal judgment." If you practice arbitrage, you'll need to use great personal judgment in dealing with varying stock prices. Remember to pronounce the last syllable "trahzh," as if it were French.
