But when health care collapsed in late 1991, funds lost nearly a quarter of their value.

In the first week and a half, Diana shares lost almost a quarter of their value, falling to just above $18 a share.

Several other groups have lost more than a quarter of their value over the last seven weeks.

It uses only 30 stocks, which together account for close to a quarter of the stock market's total value.

Within a week, worldwide markets might lose an unprecedented quarter or more of their value.

The stock has lost a quarter of its value since closing at $163 a week ago.

Assets owned by Americans lost about a quarter of their value.

They have since lost more than a quarter of their value.

Since then it has lost a quarter of its value.

HealthSouth's stock has lost nearly three quarters of its value over the last year.