Bob Doll, Chief Equity Strategist at money manager Nuveen Asset Management, examines the recent weakness in commodities and continues his ongoing question of ‘what can be sustained?’ "U.S. equities declined last week as the S&P 500 fell by more than 2.0%, which came on the heels of a new all-time high the prior week.1 Led by gold, commodities experienced volatility and declined over the past two weeks. Other detractors included disappointing first quarter Chinese economic numbers and somewhat softer U.S. releases."