It's the law of gravity: What goes up must come down.
has been borne out time and again on the stock market, as shares of hot companies soared and then plunged.
This year's standout example is health care. After rewarding investors with healthy profits in recent years, stocks of companies that deal with health needs have taken a beating.
The erosion of market values began before many people outside Arkansas had heard of Bill Clinton. Now that he is the presidential favorite, followers of the stocks are paying as much attention to him as to such conventional trends as earnings and dividends.
A Clinton victory could change the outlook, but no one knows exactly how. The analysts suspect, however, that HMOs -- health maintenance organizations -- would do well under Clinton's health care proposals, and pharmaceutical companies would come under pressure.
Like high-tech companies in the 1960s and gambling stocks in the 1970s, many health care investments carry high risks.
In late September, a Wall Street favorite, Medical Care America, won the booby prize for the year's most spectacular fall when it said its profits were unlikely to live up to expectations. The stock went to $25, from $58, in a single day. It since has slipped to $17.
Other high-flying health care stocks have come down to earth in the 1992 sell-off. Home Intensive Care has dropped 60 percent since the start of the year, while Ivax has fallen 30 percent and Cordis Corp. lost more than 13 percent. All three are based in Miami.
The experiences of health care stocks partly reflect uncertainty created by the great debate over the national medical crisis.
"All health care companies face election-year uncertainties," observed Kenneth Abramowitz, an analyst with Sanford Bernstein & Co. in New York. "Both Democratic and Republican proposals for health care . . . changes are at least slightly negative."
In addition, he said, "as managed care takes over the health care system over the next 25 years, the profit margin of virtually all companies will fall, unless they are highly innovative."
But a few HMO stocks could be beneficiaries of the changing health scene. Shares of Coral Gables, Fla.-based Ramsay-HMO Inc. are up more than 40 percent this year.
"A Clinton presidency appears more likely, and HMOs are well positioned to benefit in a more cost-conscious atmosphere," said Margo Vignola of Salomon Brothers, who recommends United Healthcare Corp.
Other analysts like it, too. Mimi Willard of Shearson Lehman calls United "one that we designate a core holding."
"Because of the company's business mix -- HMOs and health care cost management -- it should benefit from being part of the solution to our health care crisis in the 1990s," she said.
Pharmaceutical companies are viewed less favorably.
Analysts sense some form of price controls under a Democratic administration.
"Should the Clinton program be adopted, the odds increase substantially that the government would place price controls on those pharmaceuticals reimbursed by public programs," said Kent Blair of Donaldson Lufkin Jenrette. "Once such controls are enacted in the public sector, they could easily be extended to the private sector."