Small wonders: Among companies with stock market values below $1 billion, more than 500 have doubled in price this year. More than 200 have tripled.

In part, that s owed to the broad market s giddy turn since spring. The S&P 500, down 25% this year through early March, is now up 11% year to date. A sibling index for small companies, the S&P 600, is up only slightly more, but small company returns tend to be much more varied than large-company ones, with some companies astounding investors.

Below are three year-to-date highfliers, two of which are recovering from stumbles and one that s simply growing fast.

Year-to-Date Double: DineEquity

In 2007, pancake chain IHOP gorged on debt to buy Applebee s, a casual grill. Management later changed the company s name to the Scrabble accident DineEquity (DIN) . The timing of the purchase wasn t great. Sales at longstanding Applebee s locations last quarter fell 4.3% on top of a 1.7% decline a year ago. IHOP same-store sales are falling, too, albeit more slowly. The good news for investors is that Applebee s sales decline is less severe than its peer average. It seems the chain s 2-for-$20 promotion, which is really a 3-for-$20 in that it includes two entrees and an appetizer, is helping with traffic. Earnings per share are expected to rebound 38% this year on cost cutting, putting shares at a reasonable 13 times the forecast. The stock is still less than half its price of two years ago. Last quarter the company paid down only a speck of its gigantic debt. One possibility, say analysts, is that management will eventually opt to sell new shares to extinguish debt. That generally devalues existing shares, but much depends on how worried investors were about the debt to begin with. Ruby Tuesday (RT), another casual eatery, announced a stock-for-debt deal on July 20 and ended the day with a higher share price.

Hitting a Triple: Sonic Automotive

Sales for Sonic Automotive (SAH) were recently forecast to decline 11% this year after a 28% drop last year, but analysts might have to revisit their assumptions. The government s cash for clunkers program, whereby taxpayers fund cash incentives for jalopy-owners who trade in for new models with better gas mileage, started in July and has already whisked through $1 billion in initial funding. Congress is considering $2 billion more. Sonic, a dealer one-sixth the size of Auto Nation (AN), last week reported a small second-quarter profit, but the impact of the clunkers program should show up in third-quarter results. Ford on Monday said it sold 2.3% more cars in July than June. Sonic shares ended the day 14% higher.

Up Fourfold: Rino International

China and the U.S. ended two days of talks in Washington last week with only a memorandum of understanding on climate change -- that is, a vague promise of cooperation. A better gauge of Beijing s interest in clearing the air back home might lay in the profit statement of Rino International (RINO), based an hour flight from Beijing in the coastal city of Dalian. The company makes equipment that iron and steel makers use to remove sulfur and other pollutants from exhaust gasses and wastewater. The Chinese government is offering tax incentives for manufacturers who install the equipment and fines for those who don t. Rino s sales are expected to climb 22% this year and its earnings per share are seen doubling. Shares are less than nine times forecast earnings.