Our life expectancy is a sensitive piece of guesswork, and an important factor for the future sustainability of health care. Our economy depends on it.

In 1840, the record life expectancy went to Swedish women, who averaged a whopping 45 years. (Women, by the way, have a greater life expectancy than men by 5-7 years.) Compare that statistic with the prediction that, "by 2070 female life expectancy in the U.S. will be between 92.5 and 101.5 years, which substantially exceeds the forecast of 83.9 years made by the Social Security Administration in 1999."

What's led to this great change in expectation? There are several factors at play, but we can accept that a lesser prevalence of chronic diseases and disabilities is a large contributor. And with increasing breakthroughs in medicine and genetic engineering, we have to ask ourselves if the current life expectancy is still too low.

While the thought of living well into our 100s may be interesting, it may also be very expensive. "The principal factor driving growth in expenditures on health care is demand. As people get richer, they want to spend a larger share of their income on improving their health," says Bloomberg.

Yet "expensive" may mean "profits" for many large health-care service companies.

To help you analyze how the increase in life expectancy and future trends in health care may translate to the market, we list a few of the biggest health-care sector stocks below. Additionally, the stocks below have been experiencing significant increases in institutional buying-a bullish signal that Big Money believes there is more upside to these names.

What do you think? Will a generation of centenarians boost the profits of these companies? Use this list as a starting point for your own analysis.

List sorted by institutional buying as a percentage of shares float. (Click here for free, interactive tools to analyze this list of stocks.)

1. Epocrates (Nasdaq: EPOC): Medical Appliances & Equipment Industry. Market cap of $410.67M. Current price at $17.53. Net institutional shares purchased in the current quarter at 9.2M. This is equivalent to 64.79% of the company's 14.20M share float. The stock is a short squeeze candidate, with a short float at 6.86% (equivalent to 18.15 days of average volume).

2. Endocyte (Nasdaq: ECYT): Drug Manufacturers Industry. Market cap of $339.70M. Current price at $11.67. Net institutional shares purchased in the current quarter at 13.0M. This is equivalent to 50.6% of the company's 25.69M share float. After a solid performance over the last year, ECYT has pulled back during recent sessions. The stock is -12.06% below its SMA20 and -5.79% below its SMA50, but remains 13.36% above its SMA200.

3. Quidel Corp. (Nasdaq: QDEL): Diagnostic Substances Industry. Market cap of $521.76M. Current price at $15.46. Net institutional shares purchased in the current quarter at 4.5M. This is equivalent to 17.54% of the company's 25.65M share float. The stock is a short squeeze candidate, with a short float at 19.14% (equivalent to 27.04 days of average volume). The stock has gained 31.3% over the last year.

4. HealthSpring (NYSE: HS): Health Care Plans Industry. Market cap of $3.07B. Current price at $44.92. Net institutional shares purchased in the current quarter at 9.7M. This is equivalent to 15.08% of the company's 64.31M share float. The stock has gained 166.29% over the last year.

5. Pharmasset (Nasdaq: VRUS): Drug Manufacturers Industry. Market cap of $5.09B. Current price at $134.32. Net institutional shares purchased in the current quarter at 4.9M. This is equivalent to 14.91% of the company's 32.86M share float. The stock has had a couple of great days, gaining 9.1% over the last week.

6. Quest Diagnostics (NYSE: DGX): Medical Laboratories & Research Industry. Market cap of $8.97B. Current price at $56.26. Net institutional shares purchased in the current quarter at 21.1M. This is equivalent to 13.51% of the company's 156.17M share float. The stock has gained 28.38% over the last year.

7. Ironwood Pharmaceuticals (Nasdaq: IRWD): Medical Laboratories & Research Industry. Market cap of $1.53B. Current price at $15.4. Net institutional shares purchased in the current quarter at 5.0M. This is equivalent to 13.33% of the company's 37.52M share float. The stock is a short squeeze candidate, with a short float at 9.19% (equivalent to 16.26 days of average volume). The stock has gained 18.33% over the last year.

8. Questcor Pharmaceuticals (Nasdaq: QCOR): Biotechnology Industry. Market cap of $1.68B. Current price at $26.99. Net institutional shares purchased in the current quarter at 7.2M. This is equivalent to 13.11% of the company's 54.90M share float. The stock is a short squeeze candidate, with a short float at 12.73% (equivalent to 7.88 days of average volume). The stock has had a good month, gaining 17.03%.

9. Opko Health (NYSE: OPK): Medical Appliances & Equipment Industry. Market cap of $1.26B. Current price at $4.39. Net institutional shares purchased in the current quarter at 17.6M. This is equivalent to 13.11% of the company's 134.23M share float. The stock is a short squeeze candidate, with a short float at 8.03% (equivalent to 10.32 days of average volume). The stock has had a good month, gaining 29.41%.

10. Amarin (Nasdaq: AMRN): Drug Manufacturers Industry. Market cap of $1.88B. Current price at $14.23. Net institutional shares purchased in the current quarter at 14.1M. This is equivalent to 13% of the company's 108.42M share float. The stock has had a couple of great days, gaining 6.02% over the last week.

Interactive Chart: Press Play to compare changes in analyst ratings over the last two years for the stocks mentioned above. Analyst ratings sourced from Zacks Investment Research.


Kapitall's Becca Lipman does not own any of the shares mentioned above.

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