Policy Profiteering

   Secret of success on Wall Street: Buy low, sell high.
   One way to do this is through what's called short selling. For example, you agree to sell 1,000 shares of stock at $100 per share in two weeks time, but you don't have the stock yet.
   Instead, you hope that soon before the due date the market price of the stock will drop to, say, $80 per share. So just before the due date, you buy or borrow the stock at $80 and immediately deliver it, as promised, for $100 per share.
   You then get to pocket the difference -- $20 per share -- for a total of $20,000. Pretty good profit, especially if you did the whole deal on borrowed cash or borrowed stock.
   
   Now consider that you're in a position to influence the market and stock prices. For example, a senior government official announces a plan to impose tariffs on certain building materials, such as steel and aluminum.
   Instantly, the stock market in general plummets. Now suppose that some folks knew about the plan ahead of time and arranged for a short sale, expecting that stock prices will drop before delivery time.
   In a few days, the senior government official abandons the threat to raise import taxes (tariffs) and as a result the market recovers.
   Insiders then deliver the stock they sold "short," having acquired it at the lower price during the market downturn.
   Coincidence?
   Market manipulation?
   Sheer luck?
   Hmmm.

   Or it could just be incompetence and ignorance about how the market works, meaning coincidence and luck enabled the short sellers to profit.
   Or it could be deliberate market manipulation, which is illegal.