The weaker performance of the Sector Select SPDR Energy ( XLE) was due in part to its 35% stake in Exxon Mobil ( XOM) and Chevron Corp ( CVX), which are down 6.7% and 10.9% respectively this month.

FORBES: 2 Oil Stocks Bucking the Trend

Such stocks include Merck(MRK), yielding 4.14%, Chevron Corp, (CVX) yielding 3.22%, Bristol-Myer, (BMY), yielding 4.19%, DuPont, (DD), yielding 3.77%, or Verizon Communications(VZ) paying 4.71%.

FORBES: Buy the Shares of Companies Likely to Buyback Their Stock over the Next 10 Years

Among the largest underlying components of VOO, in trading today Chevron Corporation ( NYSE: CVX) is trading flat, International Business Machines Corp. ( NYSE: IBM) is up about 0.7%, and Microsoft Corporation ( NASD: MSFT) is higher by about 0.2%.

FORBES: Vanguard S&P 500 ETF Experiences Big Inflow