The nation's stock market rally helped its wealthiest tycoons double their fortunes. Investors love Indonesia these days. The country's benchmark stock index rose 115% in local currency in the past 12 months--Asia's second best performer behind China's Shenzhen SE Composite. It was No. 1 as measured in U.S. dollars. Reasons include better than expected economic growth, perceived stability, ushered in by the July re-election of President Susilo Bambang Yudhoyono, and general resilience to the global recession that dragged down many other nations' economies. No surprise then that the fortunes of Indonesia's richest business people have rebounded strongly. The collective worth of the nation's top 40 has doubled to $42 billion from $21 billion last year, and is up $2 billion from its prior peak in 2007. Of the dozen Asia Pacific jurisdictions for which we track wealth, only China has done as well (next was India; its titans have gained 65%). Nine Indonesian tycoons at least tripled their wealth since last year. The country now has 12 billionaires with a combined wealth of $28 billion, up from seven billionaires, including Low Tuck Kwong, a coal tycoon who joins the ranks this year thanks to the red hot performance of his coal outfit, Bayan Resources; its stock was up 474% in the past year. Another coal billionaire is Aburizal Bakrie, whose holding in Bumi Resources also soared in value, helping him regain his billionaire status this year after nearly losing a bundle in the global credit crisis the previous year. Indeed, global demand for Indonesia's natural resources fueled the rise of many fortunes on this list. More than one-third of the top 40 make the bulk of their money in coal, palm oil or oil and gas, including four of the five newcomers. The richest new entrant is Ciliandra Fangiono, chief executive of palm oil firm First Resources. Sandiaga Uno, partner of Edwin Soeryadjaya, also makes his debut this year thanks to his interest in coal company Adaro Energy. He is one of four tycoons whose fortunes trace back to Adaro. We also welcomed brothers Kusnan and Rusdi Kirana to the list for the first time. Their budget carrier Lion Air is now the country's second-largest airline. Handily claiming the No. 1 spot for the first time are brothers and tobacco and banking tycoons R. Budi and Michael Hartono; we combined their fortunes this year to reflect the fact that this ranking, unlike Forbes' Billionaires list, includes a number of family fortunes. Still, had they not been combined, their individual net worths of $3.5 billion apiece would have earned them the top two slots. Only three Indonesian tycoons are poorer than they were last year, due in part to better information. The minimum required to make the list was $240 million, up from last year's relatively paltry $55 million and double the $120 million required in 2007. Five of last year's list members did not meet that threshold, despite three getting richer, including Hadi Surya, whose Berlian Laju Tanker secured a 30-year contract to transport liquefied natural gas for BP ( BP - news - people ). Another notable dropoff is former vice president and presidential candidate Jusuf Kalla. Net worths were calculated using Nov. 20 stock prices and exchange rates. Privately held companies were valued by comparing them with similar publicly traded companies. Additional reporting by Keren Blankenfeld, Carolin Chen, Lan Anh Nguyen, Luisa Kroll, Noelle Lim and Simon Montlake.