SINGAPORE — What a roller-coaster ride! It took more than four years for oil to go from $35 per barrel in 2004 to just above $147 in July 2008, and less than six months to go all the way down again. Today, the oil price is two-thirds lower than its peak last year, despite Israeli military strikes in Gaza that have raised concerns about the disruption of Middle East supplies.

Although these concerns helped drive benchmark prices for oil more than 20 percent higher last week, it is the underlying fall in demand for oil, triggered by the global economic slump, that sent prices tumbling and may keep them down for much of this year, despite efforts by leading exporters to cut production.

Who are the winners and losers?