40 Under 40

40 under 40

Who are 2012's young business stars? We’ve got the CEO of a blue-chip beer brand, an airline CEO who just placed the largest order in commercial aviation history, and Warren Buffett’s new prodigy, among the Silicon Valley hotshots and others.

Since the co-founder returned to the CEO role last year, he's been bent on proving Google still has its mojo, even as he puts his own stamp on the search engine he co-founded 14 years ago. Straight out of the gate, Page closed Google's boldest acquisition to date -- the $12.5 billion purchase of Motorola. He also stripped away layers of management and shuttered dead-end projects. Google+, its self-styled "social spine," hasn't exactly been a home run -- as of last count, its 100 million active users are a drop in the bucket compared with Facebook's 1 billion. Still, Google pretty much owns the mobile ad space, pulling in north of 95% of all dollars spent on phone ads. And its Android operating system has been a runaway success. (It powers over half of all smartphones sold in the U.S.) For their part, shareholders have already voted: Google's stock is at an all-time high. This year Page leapfrogs Mark Zuckerberg to take the No. 1 slot on our list for the first time. Out of this world: Page recently invested in an asteroid mining venture called Planetary Resources, which aims to "expand Earth's natural resource base." -- Michal Lev-Ram Editors' Note: A previous version of this story incorrectly stated that Google+ had 100,000 active users. The number is actually 100 million. Fortune regrets the error.

Larry Page

Facebook's stock may have taken a beating since its $104 billion stock market IPO in May, but eight years after Zuckerberg founded the social network in his Harvard dorm room, it continues to dominate: 1 billion active users have uploaded a total of 219 billion photos and given a thumbs-up "like" 1.13 trillion times since launch. The company also released major updates to its mobile applications, and, reflecting Zuckerberg's philosophy of full steam ahead, the Facebook founder hired architect Frank Gehry to expand the company's already vast Palo Alto headquarters. Mobilize: Zuckerberg is so attached to his smart phone, he used it to write his founder's letter for Facebook's S1 stock registration -- all 2,178 words of it. --J.P. Mangalindan

Mark Zuckerberg

Marissa Mayer

Brin might have the best job at Google: turning science fiction into reality. The search giant's co-founder stepped down as president of technology in 2011 to focus on the fun stuff dreamed up in the super-secretive Google X labs. Take "Project Glass," which he unveiled in June. The goofy-looking computerized glasses let users watch videos and browse the web via a tiny display in their line of vision. In his spare time, Brin (along with his wife, 23andme CEO Anne Wojcicki) has become a bigtime philanthropist, donating $132 million to the battle against Parkinson's disease. Cash pile: Brin's net worth is estimated at $20.3 billion. -- M.L.

Sergey Brin

The consummate multitasker no longer has a day-to-day role at Twitter but he's been on a tear at Square. The fast-growing payments company has signed on more than 2 million customers, including both Romney and Obama campaigns, which use it to collect donations. In August, Square signed its biggest merchant yet: Starbucks, the king of lattes. Dorsey personally flew to Seattle to seal the deal with Starbucks CEO Howard Schultz, who now sits on Square's board. As part of the agreement, Starbucks invested $25 million in Square, helping to raise the startup's estimated valuation to a whopping $3.25 billion. Not bad for a deal that was sealed in the virtual blink of an eye. His dream job: Mayor of New York City. --M. L.

Jack Dorsey

Jensen has come a long way at Bridgewater, the world's largest hedge fund. In August the former intern became chief executive of the $130 billion, 1,200-person hedge fund firm. He remains co-chief investment officer with founder Ray Dalio, and together the team recently won the coveted Hedge Fund Firm of the Year from Institutional Investor. Jensen and his fellow execs constantly fine-tune the firm's investing bible -- the legendary set of rules that guide the firm's every investment move -- reflecting their belief that the world is now driven by policy, not markets. Om: Jensen started meditating last year, finally giving into Dalio's recommendation that he try it. The result? He's a convert. He says he has greater clarity and focus. --Katie Benner

Greg Jensen

Never mind that the success of Deese's first White House project -- the auto industry bailout -- could give President Obama's reelection campaign a critical edge in the industrial Midwest. With the economic recovery still sputtering, he's focused on helping the President create jobs and provide relief. Congressional gridlock makes progress tough, so the Belmont, Mass., native counts wins in smaller increments, pointing to efforts his team has designed: a $4 billion public-private partnership to retrofit commercial buildings, for example, or a streamlined mortgage-refinancing program that's kept a half-million people in their homes this year. "The cumulative impact of doing a lot of things like that can matter," Deese says, though he believes the remaining challenges require much bigger solutions -- and more cooperation in Washington to get them done. Networking tip: Ask real, difficult questions. People appreciate that more than small talk. --Tory Newmyer

Brian Deese

When troubled banks and countries around the world get into financial messes, they call BlackRock Solutions for help. Goldstein's analytics, risk-management, and advisory unit -- a 900-person division embedded inside asset-management giant BlackRock that generated more than $500 million in revenue last year -- has counseled high-profile clients such as the U.S. government, Ireland, and Greece. Its next challenge? Creating a trading platform that BlackRock's clients can use to trade bonds with one another, circumventing brokers (and their fees). Goldstein, who has worked at BlackRock since he was 20, was promoted in August to run BlackRock's institutional business, which has $2.2 trillion in long-term assets. Huge clients and governments will get his personal attention. To cap it off, he's the youngest person on the firm's executive committee. Favorite band: He's a deadhead. --Mina Kimes

Rob Goldstein

Call him the ultimate company man. The lanky Dutchman's first job with Heineken was as a commercial management trainee back in 1998, for which he spent six months as a "unit controller" in Helmond, Netherlands. He rose methodically, and by the time he left the Congo in 2009, where he ran commercial operations, he had more than doubled the brand's market share there and tripled its revenue. Since taking the top U.S. leadership spot in 2009, van den Brink has engineered a turnaround. Sales of Heineken lager were floundering and market share had fallen, but thanks to steps like smart advertising for Dos Equis (you've no doubt seen the "Most Interesting Man" campaign), the U.S. portfolio is up 4.1% in volume since January. Drink the Kool-Aid: He says he and his staff "have green blood." --Daniel Roberts

Dolf van den Brink

The 2012 election will be a big moment for Hispanic voters -- and by proxy for Univision, the most popular Spanish-language network in the U.S. Conde continues to roll out new initiatives at the network, which is ranked fifth overall but has been steadily stealing viewers from its rivals, especially in the 18- 34-year-old category. He recently announced UVideos, a digital network that will air all of the company's shows, and a 24-hour English language news channel for Latinos that will be produced in partnership with ABC. Most-hated jargon: Silos. --M.K. David Rhodes

Cesar Conde

Don't expect a hologram or even a famous politician's child to contribute to his newscasts. Since taking the reins at ailing CBS News (earning him a spot on last year's list), Rhodes has eschewed the fluff, flash, and other ratings bait that typically pass for news these days to focus on, um, well, news. He's lengthened the network's flagship political show, Face the Nation, put Scott Pelley in the evening anchor spot, and completely overhauled the moribund Early Show, which debuted as CBS This Morning with Charlie Rose and Gayle King in January. The strategy seems to be working. Ratings for CBS's morning and evening shows are up nicely. Stress relief: running and religion. --Erika Fry

David Rhodes

Co-founder and managing partner, Tiger Global 
 
A descendant of Peter Stuyvesant, the last Dutch governor of New York, Coleman may come from old money but he's minted a fortune in recent years thanks to the $6 billion Tiger Global hedge fund he started in 2001. With large investments in companies like Apple, <a href="http://money.cnn.com/quote/quote.html?symb=LNKD&amp;source=story_quote_link" title="">LinkedIn</a>, Amazon, Google, and Facebook, the fund reportedly gained nearly 22% through September of this year. --JM

Chase Coleman

The Avengers, released in May, reaped $207 million on its first weekend. That's the biggest movie opening ever. As head of Marvel Studios, Feige produced that and other hits, like Thor and Captain America, but he isn't resting on his laurels. It's full speed ahead on projects like Iron Man 3 and Guardians of the Galaxy. Feige was named president in 2007 but has been with Marvel since 2000 and produced both Iron Man films, which together grossed $630 million. Intern: Feige interned with Superman director Richard Donner as a film student. That was the last job application he ever filled out. --D.R.

Kevin Feige

A longtime Wall Street star, Weinstein gained Main Street fame when he harpooned the London Whale, a.k.a. J.P. Morgan's Bruno Iksil, whose disastrous derivatives trades resulted in billions in losses for the ill-starred trader's employer -- and put the hedge fund manager at the center of the J.P. Morgan saga. The performance of the $5.5 billion Saba's flagship fund is ho-hum this year, but Weinstein doesn't seem fazed: He just plunked down $25.5 million to buy the four-bedroom apartment on Fifth Avenue that had belonged to the reclusive copper heiress Huguette Clark. And he gave $1 million to New York City's Stuyvesant High School, his alma mater, to fund a library renovation. Ka-ching: Weinstein reportedly earned $90 million in 2011. --K.B.

Boaz Weinstein

He's lived on four continents, travels yearly to 25 countries, and has scaled the peaks of the pharma business to stand atop the second-biggest generic-drug operation in the world, yet George still makes time to take his oldest daughter swimming on weekends. His focused approach has seen him take Sandoz, which did $9.5 billion in revenue last year, into biosimilars. His prescient investment in biosimilars, or generic biologic drugs, has given Sandoz more than 50% of the hot market, and will probably reverse a recent dip in sales growth. It's a gene thing: The apple didn't fall far from the tree -- his father is Bill George, the best-selling author and former Medtronic CEO, who lectures on leadership at Harvard Business School. --M.K.

Jeff George

Twenty months after going private, J. Crew is hotter than ever -- just ask First Lady Michelle Obama, whose affinity for the clothing chain has been well chronicled by fashion blogs and magazines. Wadle, the head of the company's flagship J. Crew brand, is behind many of its recent coups. Under her watch, J. Crew made a big push into men's wear, expanded its website to more than 100 countries, and forged plans to sell its clothing in China this fall. Sales at the company have soared, growing in the double digits in the first half of 2012. Stress reliever: Dance parties with her two kids, every Sunday morning. --M.K.

Libby Wadle

Kamangar's contributions to the search giant, where he was employee No. 9, run deep. Among them: creating Google's first business plan and leading the product-management teams for moneymaking advertising products and web services like Gmail. Now the Tehran-born, press-shy Stanford graduate is leading the charge with YouTube, the video-sharing site that brings in over 800 million visitors a month. To further its reach, YouTube is spending over $100 million to launch 100 channels of original content. The goal: transform the service into a TV-like destination. Pivot: Kamangar was pre-med before finding his calling. --J.P.M.

Salar Kamangar

Fan wanted to be a doctor -- until the Canadian transplant interned with a cardiologist and found that life-or-death decision-making wasn't for him. So the Harvard grad turned to Wall Street. A senior trader at Merrill Lynch persuaded him to take a chance on an esoteric corner of the currency and debt markets: high-risk Mexican and Latin American credit markets, which were reeling from massive currency devaluations. He went on to chase crises from Southeast Asia to Russia, riding his success to the top of Deutsche Bank, where he co-runs investment banking and trading. He encourages young recruits to look for opportunities that have a lot of upside rather than climb well-worn career ladders. "If things don't work out, you're only six months behind your peers. If they do, you're lucky enough to be on the rocketship before it takes off." Mantra: Fortune favors the bold. (We agree.) --K.B.

Colin Fan

In 2008, Chesky and his roommate Joe Gebbia, Rhode Island School of Design alums living in San Francisco who were short on rent, decided to blow up some air mattresses and charge travelers coming to town for a place to crash. A revolution in couch surfing was born. Four years later Airbnb, the site they created -- along with their third co-founder, Nathan Blecharczyk -- is a massive platform for shelter-sharing and a poster child for the sharing economy. The company now has 400 employees and at presstime was said to be raising a third round of funding at a valuation of $2 billion. Gebbia focuses on user experience, and Blecharczyk is CTO, but Chesky runs the show, getting out in front of issues like hotel occupancy taxes and increasingly making the rounds at mogul confabs. Describing the past four years in one word, he says: "Surreal." Tambourine man: Chesky is a huge Dylan fan. --Leigh Gallagher

Brian Chesky

The CEO of the fastest-growing website in Internet history may not be a coding genius, but 19 million visit his image-sharing site every month. Silbermann is a collector with a strong design sense. But the Des Moines native knows what he likes, and it happens to be liked by a lot of other people too: It regularly beats out Twitter and Facebook in driving traffic to smaller websites. And its growth shows no sign of slowing. Pinterest added apps for the iPhone, iPad, and Android this summer, and switched to an open-registration process. (Previously users had to be invited to join.) In September, Silbermann took on a role even bigger than running a company valued at $1.5 billion. He became a father. Collect this: Silbermann never lost his childhood love for stamp collecting (but he did give up on insects and rocks). --Ryan Bradley

Ben Silbermann

Instagrammers, rejoice! You were indeed on to something when you came in droves to the new photo app two years ago. So were we: Systrom, No. 39 on last year's list, this year sold his baby to Facebook for $1 billion (because $1 million isn't cool). Systrom says the 16-person Instagram team is still independent within Facebook, and in 2013 will expand. Indeed, Systrom isn't going anywhere: "Other people sell and check out," he says, "but we have no interest in doing that. When the founders leave, that's when the soul of a company goes away." Mobilize: Word has it that Systrom will be a key player in beefing up Facebook's mobile presence. --D.R.

Kevin Systrom

A former financial analyst who quit to find her inner entrepreneur, Ransom had already started up an adventure travel company and a software company by the time she and fiance Alain Chuard created Wildfire in 2008 to help businesses market across social media platforms. It caught on like, ahem, wildfire. In 2011 the firm's revenue tripled; this year its employee count reached close to 400, and it opened offices in eight cities around the world, including Singapore and Paris. Though Ransom wasn't looking to sell, Wildfire's rapid growth caught Google's eye. The search giant acquired Wildfire for some $400 million in August. Ransom plans to stick around for the next few years, but says she already feels that entrepreneurial itch. Up next: A not-for-profit. --C.L. Michael Lazerow

Victoria Ransom

To hear Lazerow tell it, Buddy Media wasn't looking for a buyer for his marketing software startup until Marc Benioff swooped in. Some $750 million later, Lazerow has become the latest successful entrepreneur to join the Salesforce juggernaut. Lazerow, who visited Benioff at his home in Hawaii in August, says the two see eye to eye on pretty much everything. Lazerow is merging his Buddy Media team with the staff of another recent acquisition, Radian6, to create a new marketing cloud division of the company, which he will lead as chief marketing officer. "I've been given a responsibility to push the whole company forward and get it out of its own way," Lazerow says. Benioff has wasted no time propelling his newest executive forward: Lazerow gave the marketing cloud keynote address at Salesforce's massive Dreamforce 2012 conference last month in front of 80,000 attendees. Viral views: Lazerow posted a video explaining why he sold, expounding on his philosophy of living without fear following several major heart scares. It went viral, earning over 150,000 views. --Alex Konrad

Michael Lazerow

Tanaka presides over a world of opal-eyed digital zombies and pirates. GREE, the mobile social-gaming company he founded in his apartment in 2004, has become Japan's biggest social network -- of any kind. Globally it reportedly has 190 million users and expects to generate $2.5 billion in revenue this year. To gain a foothold in the West, GREE acquired U.S. mobile-game maker OpenFeint last year. The company's success has turned the boyish Tanaka into Asia's youngest self-made billionaire. Tanaka says he grew up obsessively playing NES games into the twilight hours. His parents thought he was wasting his time, he says. Clearly they were wrong. --Matt Vella

Yoshikazu Tanaka

Ek brought his much-buzzed-about Swedish music streaming service to the U.S. last year amid hopes he'd swoop in and save the music biz. His ballyhooed hookup with Facebook offered plenty of extra juice. So is it a hit? Spotify operates in 15 countries and claims 15 million active users, 4 million of whom pay for ad-free listening. Those numbers are dwarfed by Pandora's 54.9 million users, but they are growing fast and revenue is way up (150% in 2011, by some estimates). So, it must be said, are its losses thanks to mounting licensing fees (it isn't yet profitable). Still, Ek's tech savvy and vision have earned him the ear of the industry. Top travel tip: Dig that neck pillow. --E.F.

Daniel Ek

Three is a magic number -- Kickstarter's founders know this to be true. In 2012, its third year, the world's largest fundraising platform hosted the first of three $3 million--plus projects. Indeed, its nearly 3 million backers (and 4 million users) have generated $300 million for projects, ranging from a scheme to send handwritten letters to small towns en masse to a beautiful Bluetooth watch. If a project reaches its goal, Kickstarter takes 5%. And in three years the staff has grown 14-fold, to nearly 42 employees from its original group of, yes, three. On the side: Chen co-founded an art gallery in Williamsburg, Brooklyn; Strickler was a music critic for Pitchfork, the irreverent indie music website. Adler co-founded an online art magazine. --R.B.

Perry Chen, Charles Adler & Yancey Strickler

Hasenstab is one of the biggest winners from the eurozone crisis. His $60 billion Templeton Global Bond Fund has gained 10% this year, to beat all but a handful of rivals. The Ph.D.-educated contrarian is betting that Europe will stay together, despite the threat of many more years of economic hardship. Hasenstab regularly meets with policymakers around the world. Then he buys debt according to his take on a country's prospects -- not merely a benchmark index. His view of the U.S.? He hasn't owned U.S. Treasuries for years. ("We've printed way too much money," he says.) His big bet is on China's continued growth. Expert at: Skinning and chopping up chickens. (He assisted the cafeteria chef in his freshman year at Carleton College.) --S.C.

Michael Hasenstab

Rascoff has made swift progress with Zillow, the online real estate site he joined in 2005 that connects real estate agents, homeowners, mortgage lenders, and others. And with 100 million homes and apartments in its database, it has also become an invaluable tool for economists too. Since he took it public last year, Zillow's revenue has climbed and membership has soared to 37 million active users. Much of Zillow's success lies in the smooth -- and rapid -- user transition from desktop to mobile. Explains Rascoff: "It's when you're driving around that having access to real estate information is all that more critical." All in the family: Rascoff's 7-year-old daughter is pursuing an entrepreneurial venture of her own, selling perfume online. --J.P.M

Spencer Rascoff

Shih's impressive resume -- she developed Facebook's first business application in 2007, and in 2009 published The Facebook Era (the de facto social networking handbook for corporations) -- led her to launch Hearsay Social with her college friend and former Microsoft exec Steve Garrity in 2009, backed by $21 million in funding. The fast-growing platform helps large companies actively manage their social media presence across multiple sites. Equally notable is Shih's clout beyond the office. After stints working at Google and Salesforce, she counts Facebook COO Sheryl Sandberg and Salesforce.com CEO Marc Benioff as her mentors. Last December, Shih was named to the Starbucks board of directors, where she rubs shoulders with the company's CEO, Howard Schultz; Juniper Networks CEO Kevin Johnson; and Ariel Investments president Mellody Hobson. Best advice: Underpromise, overdeliver. --C.L.

Clara Shih

For a 13-year-old company built on slickly designed Bluetooth headsets, the last two years have been nothing short of a revolution -- both for Rahman and Jawbone. In 2011 he unveiled the Jambox rubberized wireless speaker, shaped like a rectangular prism, and it quickly became the top seller in its category. Later that year Rahman released the UP, a wristband computer roughly the size and weight of a Livestrong bracelet that could track an astonishing range of its wearers' activities, even waking them during their optimal sleep cycle. Many units broke after a few weeks, but Rahman's deft response -- an open letter admitting there was a problem and allowing any owner to return the UP for a full refund -- was hailed across Silicon Valley and beyond. (See feature story on Rahman at fortune.com.) A retooled UP will be released "soon," Rahman says, and hey, it could be as big a hit as the Jawbone. Most hated jargon: Bandwidth. --R.B.

Hosain Rahman

The two sisters like to get a headstart. They had their acting debut as 6-month-olds and launched their first fashion line when they were 12. Nowadays they're focused on running their fashion empire, which has grown into one of Seventh Avenue's hottest collections. Their company is home to their three core fashion lines: luxury The Row, contemporary Elizabeth and James, and mass-market Olsenboye, which is sold in partnership with J.C. Penney. The casual clothing and T-shirt ecommerce brand Stylemint round out the portfolio. Capping off a rise that has stunned even the most hardened fashion observers, the twins recently walked away with the most coveted award at the Council of Fashion Designers of America, Womenswear Designer of the Year -- fashion's equivalent of winning Best Picture at the Oscars. Baggy: An alligator backpack from The Row reportedly sold out despite its $39,000 price tag. --Caitlin Keating

Ashley & Mary-Kate Olsen

The duo's five-year-old startup is now India's largest e-tailer, clocking 50,000 shipments a day of everything from books to phones to baby-care products. Sales of $100 million were up 10-fold over last year, and the former Amazon software developers (who are not related) are consolidating their lead in India's $1.6 billion e-commerce market. They snapped up online consumer electronics firm Letsbuy, launched Flyte, an online music store this year, and just closed a fourth round of funding by a consortium including U.S. heavyweights Tiger Global, Accel Partners, and ICONIQ Capital. Growth target: To top sales of $1 billion by 2015. --R.A.

Sachin Bansal, Binny Bansal

Liu has led China's answer to Amazon to dizzying heights. The Wal-Mart-backed 360buy.com has seen 200% annual growth in revenue since Liu founded it in 2004 after his brick-and-mortar operation -- a consumer electronics shop he set up in Zhongguancun, Beijing's IT district, in 1998 -- was driven to the brink of ruin by China's deadly SARS outbreak. (Last year revenue totaled $3.3 billion.) Today Beijing-based 360buy.com is second only to Alibaba's online marketplace, a gap Liu is working on closing with the launch of an all-out price war. For cash-rich 360buy.com ($1.3 billion and counting), lower prices mean big gains in market share. Of course it also means Liu might have to forgo profit and delay his U.S. IPO until after 2013, but for 360buy.com, the end game is worth it. Hiring spree: Liu is adding 10,000 employees this year. And then next year, too. --R.A.

Qiangdong Richard Liu

The French-born CEO runs not only Russia's Amazon but its Expedia and FedEx as well. Sales at the country's largest e-commerce group have almost doubled to more than $300 million since the former BCG consultant took over last year. The challenges she faces in Russia's still infant e-commerce bazaar are intense: Less than 20% of Russian Internet users have made a purchase online, most distrust anything that doesn't involve direct personal contact, and almost all still pay in cash on delivery. Meanwhile, rivals are snapping at her heels trying to poach her trained staff. Still, Gavet, who worked in an orphanage in Russia while studying the language, is staying one step ahead. Aided by a record venture capital infusion of $100 million in September 2011, she acquired popular online fashion retailer Sapato in February and is gunning for exponential growth. Unashamed fan of: Britney Spears. --Rupali Arora

Maile Gavet

Instead of hiring an experienced outsider, the founders of IndiGo, India's most popular airline (and its most profitable one), chose Ghosh, the company's 37-year-old lawyer, to be its president. The neophyte delivered, despite his total lack of operational experience. The low-cost carrier, which has a little over $1 billion in revenue, recently started international flights and placed the largest order in commercial aviation history for 180 Airbus A320s, totaling $15.6 billion. Ghosh's secret to success? No frills, all the way. His office is small, with no receptionist and no marketing department. On business trips he stays in budget hotels with the rest of his staff. Job creator: IndiGo created 2,500 jobs in the past year. --Omar Akhtar

Aditya Ghosh

The hip 12-year-old green cleaning-product maker hit $100 million in sales faster than consumer brand phenoms like Nike, Ben &amp; Jerry's, and Snapple. Rivals took notice. For much of the past year co-founders Eric Ryan and Adam Lowry have been busy "seeing off the pretenders," as Lowry puts it. In early August the duo faced a major decision: Should they sacrifice their independence to merge with Belgian competitor Ecover? Pulling the trigger doubled the size of their company's revenue, and Lowry and Ryan will continue as before, across the larger company -- with Lowry heading up sustainability efforts and Ryan overseeing brand projects in the mold of Method's fast-selling product line at Target, a collaboration with designer Orla Kiely. "We like to say that we sold out, but we didn't sell out," Ryan jokes. "I've started a company, I've sold a company, but I've never transitioned a company before." Water babies: Both Lowry and Ryan hit the water to de-stress: they're serious sailors. --A.K.

Eric Ryan & Adam Lowry

CEO Hyman and co-founder Fleiss, both Harvard Business School grads, were all too familiar with the frustration of peering into a closetful of clothing but having nothing to wear. Their three-year old company lets women rent a designer dress at a fraction of the purchase price, making luxury fashion affordable, at least for a night. Wary designers needed convincing to come onboard at first, but what a difference three years makes: Today Rent the Runway has 3 million members who have rented outfits from over 160 designers. The site is especially popular on college campuses nationwide; a targeted program tasks 1,000 students to promote Rent the Runway at their schools, helping them develop entrepreneurial and marketing skills. De-stressing tactics: Hyman calls her parents on the way home from work every day; Fleiss goes for runs. --C.K.

Jennifer Hyman & Jennifer Carter Fleiss

The dapper Italian started a new gig this summer at PepsiCo as the company's first chief design officer. Trailblazing a role at a Fortune 500 enterprise is nothing new for Porcini. Prior to PepsiCo, he spent 10 years at 3M, where he started as a design manager and worked his way up to become the company's first chief design officer. The self-described change agent evangelizes for the incorporation of design principles into all of an organization's processes -- something he'll do from his powerful perch at PepsiCo to drive growth and innovation. Clotheshorse: Porcini owns 90 pairs of shoes and 30 watches. --Beth Kowitt

Mauro Porcini

Think you're busy? This year the enterprising ramen enthusiast expanded his nearly 500-employee empire to four Momofuku restaurants in New York City, one in Sydney, and three in Toronto, plus two bars and five Momofuku Milk Bar bakeries in New York. His restaurants have won a diehard following, and his food magazine, Lucky Peach, has been a hit. Along the way, the son of Korean immigrants has picked up three prestigious James Beard awards. Screen test: Chang played himself on HBO's New Orleans drama, Treme. --D.R.

David Chang

It may surprise some that five-year-old Polyvore is having its best year yet. The social design hub has seen its highest traffic ever this year, and will more than double its advertising revenue. Users love sharing their own "sets" of outfits or interiors. Advertisers love the data they get from Polyvore, which sends reports on the most popular brands. (The sets also funnel traffic to sites like Net-a-Porter and Neiman Marcus.) Lee is quick to credit much of Polyvore's success to co-founder Pasha Sadri (now CTO), from whom she took the CEO title this year. Her first order of business was opening a New York office. The "infinite fashion magazine," as Lee calls it, is only getting bigger from here. Her No. 1 cause: Get more women into computer science. --D.R.

Jess Lee

Britt founded Smart Woman Securities, a not-for-profit that educates female students about investing, while an undergrad at Harvard. As a junior, she cold-mailed Warren Buffett asking if he would meet with her members. To her surprise, he agreed. That kind of chutzpah has served the Kansas native well. After she graduated from Harvard Business School in 2009, she landed on Buffett's doorstep at Berkshire Hathaway in Omaha once again; this time Buffett wound up hiring her as his financial assistant. She hasn't looked back since. Buffett made her chairman of Berkshire-owned framing company Larson-Juhl in 2012 (and had her recruit the CEO), and then did the same at paint retailer Benjamin Moore. With Buffett as a mentor, it's safe to say big things are in Britt's future. Make that a bushel: When Britt, who grew up on a farm, first visited Berkshire Hathaway after HBS graduation, she showed up with a bushel of sweet corn (and tomatoes) as a gift. --C.L.

Tracy Britt

Founder and CEO, Change.org Almost everyone knows of Trayvon Martin, whose killing in Florida this year ignited national outrage, but few know of Rattray, the man who helped make his death a cause célèbre. Rattray's five-year-old site, Change.org, took off last year and now counts more than 20 million users, generates a jaw-dropping 15,000 petitions per month, and will bring in some $15 million in revenue this year, mostly from nonprofit advertising. Victories include persuading Universal Pictures to add an environmental message to the promotional website for The Lorax, pushing Seventeen to vow not to Photoshop out its models' curves, and enabling Martin's parents to draw 2 million signatures on a petition that even pulled the President into the ensuing fray. 
 
Hot wheels: Rattray still drives a 1996 Toyota Camry. --Anne VanderMey

Ben Rattray

The same wide-eyed University of Southern California student who hacked a Bluetooth network from a record-setting distance of over a mile away and scanned celebrities' phones on the red carpet of the 2005 Academy Awards has turned his free mobile security application, Lookout, into one of the most downloaded apps on the Android. (It released for iOS platforms in 2011.) Lookout uses its algorithm-based Mobile Threat Network to scan your smartphone for Malware and other unwanted intrusions. A serial entrepreneur, Hering was able to raise $75 million to fuel his San Francisco--based startup's rapid growth. In 18 months Lookout has tripled in size, largely through deals with major telecom providers like Sprint, T-Mobile, and Verizon. It now has more than 25 million users and is valued at $1 billion. Fave hobby: Umm ... hacking. --Eli Epstein

John Hering

When self-described "problem solver" Binta Brown talks, elected officials listen. It doesn't hurt that she's also one of the country's top black fundraisers, tapping her extensive network to fund political, humanitarian, and cultural initiatives, all while working as a corporate lawyer at Kirkland &amp; Ellis (where she recently made partner). The American Theatre Wing, the New York Philharmonic, and Barnard College (where she is the youngest trustee) have all benefited from Brown's fundraising skills, and she has served as an adviser to New York governors Elliot Spitzer and Andrew Cuomo and to Hillary Clinton when she was a senator. But Brown says she's taking a break from politics for now. Her next goal? Help fund more woman-owned tech startups. Stress reliever: Rocking out on her electric bass. --O.A.

Binta Niambi Brown

Khan's web-based tutorials have led many to rethink the way kids learn. Inspired by the nonprofit's meteoric growth, traditional universities like Harvard and MIT have begun experimenting with offering free online courses of their own. The four-year-old nonprofit Khan Academy, which offers courses spanning trigonometry to art history and has attracted donations from the likes of John Doerr and the Bill &amp; Melinda Gates Foundation, now draws over 5 million visitors a month; its YouTube channel has over 180 million views, and counting. And Khan's first book, in which he lays out his vision for online universal education, hits shelves this month. School rules: Khan has four degrees - three from MIT and an MBA from Harvard. --M.L.

Salman Khan

It's a family calling. A fifth-generation member of the NAACP, Jealous became its youngest president in 2008, having spent much of his early career as a journalist, investigating official corruption and looking out for the little guy (followed by a stint setting up Amnesty International's U.S. human rights program). A Rhodes Scholar, Jealous has brought some serious management chops to the task. Under his shrewd leadership, the civil rights organization's revenue has grown 10% annually, as its donor base has swelled almost 10-fold. Now that Jealous has put the NAACP's finances in order, he's serious about helping its hardest-hit members do the same for themselves. With black unemployment at record highs, Jealous has expanded its programs to include economic literacy training, as well as taking education, health, and environmental justice initiatives national. Need for speed: Swooshing down frozen mountains as a kid with his Maine-bred dad turned Jealous into an avid skier. --Benjamin Schenkel

Benjamin Jealous

Yes, he was born with the proverbial silver spoon in his mouth, as heir to the enormous New World Development real estate and retail empire founded by grandpa Cheng Yu-Tung. But Cheng is making his own mark on the Hong Kong--based company's sprawling operations. The Harvard-educated scion, who has worked at Goldman Sachs and UBS, is the executive director of NWD, which has a market cap of $8 billion, and also Chow Tai Fook, China's $7.3-billion-a-year answer to Tiffany &amp; Co. In 2009 he launched a luxury-goods company to sell European brands in Asia and opened a new brand of eco-friendly shopping malls-cum-art galleries in China called K11. Alter ego: Cheng decorates his office with his own art. --O.A.

Adrian Cheng

Before you knock York for being the son of the team's owners, consider this: Last season, the 49ers' head coach, Jim Harbaugh, and GM Trent Baalke were both in their first year, both put in place by the young former Guggenheim Partners analyst, and the team made the playoffs for the first time since 2002. Harbaugh, whom York had to woo in a scrutinized public process, gelled with QB Alex Smith and got Coach of the Year. Off the field, York hired Gideon Yu, former CFO of Facebook, to be the team's president, and secured fat financing for the construction of a new $850 million stadium, set to finish in 2014. Personal hero: His maternal grandpa, whose personal credo was "guts and drive." --D.R.

Jed York

To hear Cohler tell it, his career success is the result of several fantastic opportunities. But that's just part of the story. As one of the earliest employees at Facebook and LinkedIn, Cohler played significant roles in the growth of both social networks -- and became fabulously wealthy to boot. (His Facebook shares were worth a reported $680 million at the IPO.) When he joined Benchmark Capital in 2008, he became the youngest general partner at the venture capital firm. Now New York City--bred Cohler is cementing his rep as a bigshot, backing promising startups like Instagram, Dropbox, and Asana, and using his experience and connections to advise and recruit talent for them. Near miss: Cohler toyed with becoming a professional musician, but figured he wasn't good enough to make it. --J.P.M.