(FORTUNE Magazine) – Later this summer (in the Sept. 5, 2005, issue, to be exact) FORTUNE will publish its 15th annual 100 Fastest-Growing Companies list. While we work to finalize the new roster, we're examining some of the compelling stories from last year's group (for the complete list see fortune.com/fastest), here and in the following two issues. Three-year stock market return--along with earnings growth and revenue growth--is one of the criteria used to rank the companies each year. But making it to the list hardly guarantees that a company's shares will soar in the future. Here's a look at the best- and worst-performing stocks from last year's list.

The Best

MERITAGE

MTH

Price

$80

Total return

145.7%

2004 rank: 51

This homebuilder, based in Arizona, continues to ride the real estate boom. (Fellow builders on last year's list, such as Hovnanian, up 94%, and D.R. Horton, up 65%, have also jumped.) Geographically it's in a sweet spot: As of May, the average sale price of a house rose more in the West year-over-year than in any other region of the country, according to the National Association of Realtors. Meritage shows no sign of slowing: It has a five-year average return on equity of 30% and reported first-quarter revenues of $551 million, 30% higher than the year before.

HI-TECH PHARMACAL

HITK

Price

$28

Total return

105.7%

2004 rank: 90

Hi-Tech Pharmacal makes branded and generic liquid pharmaceuticals, and specializes in the growing market for over-the-counter diabetes products. (Researchers from the World Health Organization expect the number of people diagnosed with the disease in the U.S. will triple to 30 million by 2030.) The success of its sugar-free Diabetic Tussin cough syrup and DiabetiDerm moisturizing lotion--diabetics are susceptible to severe dry skin and resulting infections--helped drive a 50% increase in earnings, to $3.2 million, in its most recent quarter. The Amityville, N.Y., company has nine new products awaiting FDA approval, no debt, and $4 per share in cash on its books.

TALX

TALX

Price

$28

Total return

100.3%

2004 rank: 35

TALX is a "business process outsourcer." What does that mean? Its technology helps 7,000 clients streamline processes like payroll, W-2 filing, and immigration compliance. That's lucrative work: Gross margins now top 59%. But TALX's secret weapon is The Work Number, a database with 107 million employment records, used to verify employment and income by potential employers, government agencies, and mortgage lenders. In fiscal 2005, The Work Number's revenues increased by 40%, to $65 million, driving a 27% gain in overall sales for the St. Louis firm. The stock split three-for-two in February.

The Worst

POSSIS MEDICAL

POSS

Price

$10

Total return

60.3%

2004 rank: 23

Possis lives and dies by sales of its AngioJet, a medical device used in the removal of bloodclots from arteries and veins (a process called thrombectomy). In September the Minneapolis company said that a study it commissioned on the use of the AngioJet in treating heart attack patients had produced inconclusive results. The stock dipped. But it really tanked when Possis lowered earnings guidance for the year in October, citing decreased sales prospects as a result of the study. In May, Possis reported a 67% drop in quarterly profits from the year before.

DORAL FINANCIAL

DRL

Price

$15

Total return

59.9%

2004 rank: 88

This mortgage lender based in San Juan, Puerto Rico, lost almost $4 billion in market value in the first five months of 2005. In January, Doral reported a $95 million pretax loss from investing activities after ending up on the wrong side of a rate move while hedging its interest-only loan portfolio. In March, Standard & Poor's downgraded Doral's debt. In April, Doral announced it would restate its earnings for the previous four years to reflect a more conservative accounting of the value of its mortgage securities. That inspired an informal investigation by the SEC. In mid-May the Nasdaq threatened to delist its preferred stock for reporting noncompliance.

UTSTARCOM

UTSI

Price

$7

Total return

51.7%

2004 rank: 37

UTStarcom grew quickly selling wireline, wireless, optical, and switching technologies in China. But increased competition in the Chinese mobile-phone business has severely cut its profitability there. The Alameda, Calif., company is expanding into new markets like Japan but burning through its reserves: Its cash on hand shrank from $699 million in December 2004 to $389 million in March 2005. In May UTStarcom reported first-quarter net income of $38 million, vs. $54.8 million for last year's first quarter, and said its fiscal 2005 sales might come in as much as 50% lower than in 2004.

June 24, 2005. From Aug. 16, 2004 through June 24, 2005.