What can stop the rally?

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Pisani's market open: Q4 market leaders

Another day, another new high. Ebola, Ukraine, ISIS—nothing has killed this rally. It's the 39th time this year the S&P 500 has closed at a new high.

We also have record earnings, near-record profit margins—9.7 percent for the S&P 500, well above the 10-year average of 8.5 percent—and declining unemployment.

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Several beaten-up sectors have rebounded nicely. Housing stocks in particular have been on a tear recently The SPDR Homebuilders ETF is above its highs in the late summer and not far from an historic high.

Still, the market leaders in the fourth quarter are all defensive: Utilities, Healthcare, and Consumer Staples.