YAHOO [BRIEFING.COM]: The S&P 500 settled lower by 0.8% after early strength turned into afternoon weakness.

Today's headline event came in the form of Ben Bernanke's testimony before the Joint Economic Committee. During his remarks, Chairman Bernanke said premature tightening of monetary policy could stall the pace of recovery. This followed weeks of conflicting remarks from FOMC members, which sparked speculation regarding possible changes to the Fed's policy course.

However, those voices were echoed again by the afternoon release of the FOMC minutes from the May 1 meeting. The minutes indicated that some members expressed their willingness to slow asset purchases as early as June, provided economic conditions warrant the change.

Equities spiked at the start of Chairman Bernanke's testimony, but sellers made their presence known this afternoon as the major averages slumped to session lows.

While the afternoon decline occurred around the release of FOMC minutes, the move was isolated to the stock market as the 10-yr yield held near its session high of 2.04%, and the Dollar Index maintained its gain of 0.4% near 84.25.

The utilities and telecom sectors led to the downside as traders continued to dump income-oriented names. Including today's 1.6% decline, the utilities sector is down 5.0% month-to-date.

Elsewhere, the energy space lost 1.2% as crude oil declined 2.1%. The energy component ended at $94.18 per barrel, and weighed on the growth-sensitive sector.

Another commodity-related group, materials, ended among the laggards as steelmakers underperformed. The Market Vectors Steel ETF (SLX 42.61, -0.59) settled lower by 1.4%.

Cyclical sectors felt the brunt of the afternoon weakness. Similarly, the Dow Jones Transportation Average was unable to escape the selling as the bellwether complex settled lower by 1.6%.

Only consumer staples and health care were able to settle near yesterday's closing levels. The health care space was supported, in part, by Pfizer (PFE 29.30, +0.52) after the company announced plans to split off its animal health business Zoetis (ZTS 33.55, +0.51).

The CBOE Volatility Index (VIX 14.08, +0.71) ended near its highest level of the day as today's selloff increased near-term volatility expectations.

Reviewing today's economic data, existing home sales improved modestly in April, but still fell short of the 5.00 million barrier. Sales increased to 4.97 million from an upwardly revised 4.94 million (from 4.92 million) in March. The Briefing.com consensus expected home sales to increase to 4.98 million.

Also of note, the weekly MBA Mortgage Index fell 9.8% after declining 7.3% in the prior week.

Tomorrow, weekly initial claims will be reported at 8:30 ET while the March FHFA Housing Price Index and April new home sales will be released at 9:00 ET and 10:00 ET, respectively.DJ30 -80.41 NASDAQ -38.82 SP500 -13.81 NASDAQ Adv/Vol/Dec 634/2.11 bln/1872 NYSE Adv/Vol/Dec 658/854.7 mln/2381

3:35 pm : Commodities slid lower this afternoon post-FOMC minutes. Crude oil futures slid down near $94 barrel, precious metals and copper sold off and natural gas ended near the unchanged line.

Crude oil was as high as $96.19/barrel, but sold off over $2/barrel and fell as low as $94.02/barrel. June crude oil ended the day $1.85 lower at $94.25/barrel. June natural gas lost $0.01 at $4.18/MMBtu.

Sellers came out in the afternoon, causing gold and silver to extend losses. June gold fell $17 to $1384.30/oz, while July silver fell $0.19 to $22.42/oz. July copper gained two cents to $3.38/lb.