The dramatic slide in the price of gold in the past week has reversed a rise that for more than a decade has been steady and seemingly inexorable. The sudden fall ‑ in which prices plummeted 9 percent, to $1,347.40 an ounce, on Monday, the biggest two-day loss percentage since 1983 ‑ has put goldbugs, who are by definition pessimistic lovers of certainty, into a state of high anxiety. When the commodity of last resort so conspicuously fails to hold its value, the world becomes scarier place.