On a good day for the market, the Nasdaq has risen 0.5%, the S&P 500 has increased 0.6% and the Dow has moved up 0.5%. The healthcare sector is the category of stocks relating to medical and healthcare goods or services. This sector includes hospital management firms, health maintenance organizations (HMOs), biotechnology and a variety of medical products. Stocks in the healthcare sector are often considered to be defensive because the products and services are essential. Even during economic downturns, people will still require medical aid and medicine to overcome illness. Having a consistent demand for goods and services makes this sector less sensitive to business cycle fluctuations.

Company Market Cap Percentage Change
VIVUS (Nasdaq:VVUS) $1.15 billion +9.8%
Ariad Pharmaceuticals (Nasdaq:ARIA) $3.15 billion +6%
Auxilium Pharmaceuticals (Nasdaq:AUXL) $864.6 million +4.8%
Pharmacyclics (Nasdaq:PCYC) $4.25 billion +3.3%
Genomic Health (Nasdaq:GHDX) $833 million +3.1%
NPS Pharmaceuticals (Nasdaq:NPSP) $846.5 million -2.8%
ISIS Pharmaceuticals (Nasdaq:ISIS) $1.01 billion -2.1%

Broker Summary: TD Ameritrade Thinkorswim

VIVUS (Nasdaq:VVUS) is up 9.8% to reach a current price of $12.60 per share. So far today, the company's volume is 4.9 million shares.

Ariad Pharmaceuticals (Nasdaq:ARIA) has risen 6% and is currently trading at $20.07 per share. So far today, the company's volume is 5.2 million shares, 1.4 times its current daily average.

Auxilium Pharmaceuticals (Nasdaq:AUXL) has risen 4.8% to hit a current price of $18.41 per share. The company is currently trading a volume of 456,775 shares. This is one times its current three-month average.

Pharmacyclics (Nasdaq:PCYC) is at $63.08 per share after an increase of 3.3%. The company's volume is currently 166,944 shares for the day, lighter than yesterday's volume of 931,140 shares.

Rising 3.1%, Genomic Health (Nasdaq:GHDX) is currently trading at $27.92 per share. This morning, the company is trading a volume of 45,026 shares.

NPS Pharmaceuticals (Nasdaq:NPSP) is currently trading at a share price of $9.50, a 2.8% decline. At 337,035 shares, the company's volume so far today is 0.3 times the current daily average.

ISIS Pharmaceuticals (Nasdaq:ISIS) has decreased to $9.77 per share, a 2.1% fall. So far today, 558,234 shares have changed hands. This is 0.4 times the current three-month average.

The Bottom Line The nature of the market is such that stocks will have good days and bad days. It is important to weigh current activity against historical performance when making any investment decisions. Tools like valuation ratios and profit margins, however, are only as useful as the context you put them in; remember to take historical data and competitor performance into account.