The major averages hover near their highs at midday with the Nasdaq Composite (+0.5%) trading just ahead of the S&P 500 (+0.3%).

Equity indices have spent the first half of today's affair in a slow, but steady, updraft that has been underpinned by strength in the largest sectors by weight. To be fair, economic data released this morning has been positive. The second estimate of third-quarter GDP was revised up to 3.2% from 2.9% (Briefing.com consensus 3.0%), thanks to an upward revision to personal expenditures growth. Separately, November Consumer Confidence (107.1; Briefing.com consensus 100.0) also surpassed expectations.

Eight of eleven sectors sport midday gains, paced by heavily-weighted groups like health care (+1.0%), technology (+0.5%), and financials (+0.3%). Most cyclical sectors trade in the green, overshadowing a 1.6% decline in the energy sector.

The energy space has struggled since the start amid growing worries that tomorrow's OPEC meeting will not produce an agreement to freeze or cut production. A technical OPEC meeting came and went without any signs of an impending agreement and Iranian oil minister Bijan Zanganeh said today that his country will not take part in any production cuts. WTI crude trades lower by 3.8% at $45.29/bbl, and volatility is expected to persist, considering the official OPEC meeting will take place tomorrow.

On the upside, the health care sector (+1.0%) has been boosted by relative strength in biotechnology, which in turn has helped the Nasdaq stay ahead of the S&P 500. The iShares Nasdaq Biotechnology ETF (IBB 281.91, +1.92) has climbed 0.7% today.

Other influential groups have also contributed to today's advance. The consumer discretionary space (+0.3%) trades just ahead of the broader market, which has masked a 4.0% spike in the shares of Tiffany (TIF 81.25, +3.11) after the jeweler reported above-consensus results and reaffirmed its guidance.

Treasuries flashed modest losses this morning, but a reversal has ensued. The benchmark 10-yr note sits just above its flat line, pressuring its yield one basis point to 2.31%.

Economic data included Q3 GDP, Case-Shiller 20-city Index, and Consumer Confidence:

• The second estimate for third quarter GDP showed growth was revised up to an annual rate of 3.2% (Briefing.com consensus 3.0%) from 2.9% in the advance estimate while the GDP Deflator was revised down to 1.4% (Briefing.com consensus 1.5%) from 1.5%
• The Case-Shiller 20-city Index for September showed an increase of 5.1% while the Briefing.com consensus expected a reading of 5.2%
• The Conference Board's Consumer Confidence Index surged to 107.1 in November (Briefing.com consensus 100.0) from an upwardly revised 100.8 (from 98.6) in October
  • Strikingly, most consumers were surveyed before the presidential election