2013’s Top People in Business

—Cultural impact
—No. 1 revenue gainer
—No. 2 stock price gainer

It is no Secret that Elon Musk is a triple threat: The co-founder of PayPal has gone on to disrupt aeronautics with Space Exploration Technologies, known as SpaceX; shake up the auto business with Tesla Motors (TSLA); and retool the energy sector with SolarCity. (He is CEO of the first two companies and chairman and largest shareholder of the third.) But 2013 was an especially notable year for Musk, as investors and consumers wholeheartedly embraced his ideas and vision.

After a rocky start a decade ago, Tesla has emerged to become the world's most prominent maker of all-electric cars. Revenue at Tesla is up more than 12-fold for the first three quarters of the year, and the company is on track to top $2 billion in sales in 2013.

The stock is up more than fourfold year to date, and that's after giving back some gains when recent vehicle sales missed some analysts' estimates. (A series of troubling car battery fires has not helped.) And just as SpaceX has helped reignite interest in space exploration, Musk's plans for a "hyperloop" between San Francisco and Los Angeles got Americans buzzing about ultra-high-speed transit when Musk released his design plans in August.

Musk's creations have already made him tremendously wealthy — Bloomberg Wealth says he is worth $7.7 billion — but it is his audacity and tenacity that make him Fortune's Businessperson of the Year.

—Adam Lashinsky

2 The Activist Investor

The world's corporate leaders got a blunt warning this year: No company is too big or valuable to escape the threat of increasingly aggressive activist investors.

Carl Icahn and David Einhorn bought into Apple, the world's most valuable company (market cap: $467 billion), and loudly demanded that it return more cash to shareholders; Apple (AAPL) expanded its stock buybacks not long afterward, and now Icahn wants even more. Jeffrey Ubben invested in Microsoft (MSFT) more quietly, but one can't help noticing that four months later, the tech giant put him on its board of directors and CEO Steve Ballmer announced he was stepping down earlier than planned.

Other activists are pushing for change at J.P. Morgan Chase (JPM), PepsiCo (PEP), UBS (UBS) — no company is immune.

Activists' new strength isn't mysterious. Major institutional investors are sending dollars to activists, having noticed that activist funds overall have been outperforming the market averages. That's a big reason activist funds' assets have mushroomed from $12 billion a decade ago to over $89 billion now, says Hedge Fund Research.

Activists' clout could expand even more as they go global. (Daniel Loeb has tried to shake up Sony (SNE), for example.) But funds' thunder might quiet if their returns shrivel, a possibility that reflects a nagging doubt about their performance. The activists have done well in a rising market. The sterner test will come when they have to work their magic in a falling one.

—Geoff Colvin

3 'Pony' Ma Huateng

Co-founder and CEO, Tencent

Ma's Internet empire, Tencent, this year became China's most valuable non-state-owned company, with a market value of more than $95 billion, thanks to a 61% surge in the stock price since January. (Shares are up nearly 10,000% — no, that's not a typo — since its 2004 IPO.) Company co-founder Ma, in turn, became one of China's richest tech entrepreneurs (estimated net worth: $10 billion, behind No. 24 Robin Li of Baidu) but arguably the most powerful.

He first conquered the Chinese market with his QQ chat service. Now he's setting his sights on expansion around the world: Tencent was reportedly vying for a stake in the popular U.S. app Snapchat in November. Last year it inked a deal with Activision Blizzard (ATVI) that makes Tencent the U.S. gamemaker's exclusive launch partner of a Chinese version of videogame Call of Duty. Ma has his sights set beyond China — and technology.

This year he began heavily promoting Tencent's WeChat messaging app in international markets, and in November, Ma joined another Chinese Internet billionaire, Alibaba founder Jack Ma, to announce the first online insurance business in China. Analysts responded: "Huh? Insurance?" But it seems this tech star is already charting his next move.

—Scott Cendrowski

4 Angela Ahrendts

CEO, Burberry

—Most Powerful Women
—Returnee

Ahrendts was already having a banner year as the CEO of British fashion house Burberry. The stock was up 29%, vs. the FTSE 100's 10%, despite fears of a slowdown in greater China and continued ennui in Europe -- when she shocked the luxury and tech worlds with news that she was decamping to Cupertino, Calif., to head up Apple's retail and online stores. Ahrendts takes the reins in 2014, and she will oversee an operation with some $20 billion in annual sales (compared with Burberry's $3.2 billion). Analysts expect that she will play a role in helping define Apple's future, especially as technology companies move into new areas, such as "wearables" like Internet-connected watches, eyewear, and other gadgets that are in desperate need of a style makeover. (Ahrendts is credited with helping bring a more youthful image to the 157-year-old trench-coat maker.) Ahrendts's new role makes her the top woman exec at the house that Jobs built, and her success, while critical to Apple's future, will be no easy feat. The last executive to head up the tech giant's retail operations was out after less than a year. If she pulls it off, Ahrendts could be a strong contender for the top job.

—Beth Kowitt

5 Reed Hastings/Jeff Bewkes (tie)

CEOs of Netflix and Time Warner

—Returnees
—No. 3 stock price gainer (Netflix)

It has been three years since Fortune named Reed Hastings businessperson of the year; shortly afterward, Jeff Bewkes, CEO of Time Warner (TWX), compared Netflix (NFLX) to the "Albanian army"—unlikely to take over the world. There's little dispute now that the business Hastings leads is ready for battle. Its programs are Emmy winners (House of Cards) and buzz generators (Orange Is the New Black), its stock price has soared (up 100% since late 2010), and for the first time it has more paying subscribers than HBO. But Netflix's encroachment doesn't seem to be cramping Bewkes's style these days: Time Warner stock has more than doubled in three years, and it is up 40% for the year, buoyed in part by the media giant's decision to spin off its Time Inc. publishing unit (Fortune's parent). Once he sheds Time Inc., Bewkes will be left with a more focused movie and television business, one that includes HBO. (He already hived off cable networks and AOL (AOL).) If Netflix is the Albanian army, Bewkes's Time Warner might well be the U.K.—no longer a sprawling empire, but a prosperous place with a clearer sense of identity and purpose.

—A.L.

6 Jeff Bezos

Founder and CEO, Amazon

—Cultural impact
—Returnee

Bezos defied expectations again this year, sacrificing company profits nearly two decades after founding Amazon (AMZN) to chase (and potentially corner) new markets. The Seattle-based company plowed ahead with its same-day grocery-delivery efforts and partnered with the ailing U.S. Postal Service to allow Sunday delivery in some U.S. cities. Bezos's boldest move? Buying the Washington Post for $250 million with his personal venture fund. Still, his eclectic strategy has paid off in the past, and Wall Street remains as bullish as ever on the stock, up some 40% year to date.

—JP Mangalindan

7 Akio Toyoda

CEO, Toyota

—Turnaround story

The Toyoda scion says he follows two rules: "Make ever better cars. And if it doesn't offer fun, then it is not a car." He's succeeding on both counts. Just a few years after the company suffered an embarrassing recall that left a trail of lawsuits (plus the aftermath of a devastating tsunami), Toyota (TM) is back. Toyoda is steering his family's company toward record-high sales of 10 million cars and trucks, as well as record high operating profits, keeping it No. 1 in the world. At the same time he's injecting much-needed flair into its vehicles' design and engineering.

—Alex Taylor III

8 Larry Page

Co-founder and CEO, Google

—Cultural impact
—Returnee

Page's seemingly paradoxical formula to re-energize Google (GOOG)—more focus and more moon shots—is paying off handsomely. Shares this year passed the $1,000 mark, pushing Google's value ahead of Microsoft's and behind only Apple's and Exxon's (XOM) among U.S. companies. As if making sure Google stays No. 1 in search, ads, mobile, online video, maps, browsers, and more was not enough, Page has launched Google's latest zany venture: an anti-aging startup named Calico.

—Miguel Helft

9 Warren Buffett

Chairman and CEO, Berkshire Hathaway

—Cultural impact
—Returnee

He began the year devouring H.J. Heinz, the world's largest ketchup maker, for $23 billion, in partnership with Brazil-based 3G Capital. Now Buffett sits on more than $40 billion in cash, thanks in part to his gutsy investments in companies like Goldman Sachs (GS) and Bank of America (BAC) when others panicked during the 2008 financial crisis. As Buffett's pile of cash grows, it's ever more likely that Berkshire (BERK) will make another big acquisition. The Oracle of Omaha hit another milestone this year. In May he joined Twitter and already has over 700,000 followers.

—Patricia Sellers

10 Marissa Mayer

CEO, Yahoo

--Cultural impact
--Most Powerful Women
--40 Under 40

She bought Tumblr for $1.1 billion and revamped Yahoo Mail and the company's Flickr photo-sharing site. And though Mayer's overhauls (from products to workplace policies) stir controversy, she has lifted Yahoo's (YHOO) user base to 800 million while the stock price has almost doubled this year. Those accomplishments help explain why Mayer, 38, has achieved an unprecedented trifecta: the only executive ever to earn a spot on the Businessperson of the Year list, Fortune's Most Powerful Women list (at No. 8), and Fortune's 40 Under 40 rankings (No. 1).

--P.S.

11 Richard Anderson

CEO, Delta Air Lines (DAL)

--Turnaround story

The successful integration of Northwest Airlines in 2010 propelled Delta's bottom line and its stock, which is up 127% year to date.

12 Mark Zuckerberg

Founder and CEO, Facebook (FB)

--40 Under 40
--Cultural impact
--No. 3 profit gainer
--Returnee

Mobile revenues rose this year, and investors have pushed shares up 79% for the year.

13 Mark Parker

CEO, Nike (NKE)

--Cultural impact

Launches of the buzzy FuelBand and the Flyknit Racer shoe helped Parker, a former track star, boost Nike's stock some 50% this year.

14 Jack Dorsey

Executive chairman, Twitter; CEO, Square

--40 Under 40
--Returnee

Dorsey continues to wear two hats, running mobile-payments platform Square while chairing newly public Twitter.

15 Ajay Banga

CEO, MasterCard (MA)

--Returnee

The move to cashless and mobile transactions is benefiting Banga's payments company; some think the stock, now at about $735 a share, could go to $1,000.

16 Howard Schultz

Chairman and CEO, Starbucks (SBUX)

--Cultural impact
--Returnee

Schultz is brewing more than coffee (see Leadership Q&A), which has helped boost sales and profits, and drove a 51% gain in the stock this year.

17 Carol Meyrowitz

CEO, TJX Cos. (TJX)

--Most Powerful Women
--Returnee

The retailer is on a roll: It launched a new e-commerce platform and plans to add T.J. Maxx, Marshalls, and HomeGoods stores in the U.S.

18 John Martin

Chairman and CEO, Gilead (GILD)

A pipeline of hepatitis drugs has investors excited about the company and Martin, once No. 6 on a Harvard Business Review list of the world's best-performing CEOs.

19 Masayoshi Son

Chairman and CEO, Softbank

The Japan-based telecom and Internet behemoth got even bigger in 2013 with its acquisition of U.S. carrier Sprint.

20 Tadashi Yanai/Amancio Ortega (tie)

CEO, Fast Retailing/Co-founder, Inditex

--Cultural impact

Fast Retailing, which runs Uniqlo, and Inditex, Zara's parent, win with "fast fashion" offerings.

21 Jeff Sprecher

Founder and CEO, IntercontinentalExchange (ICE)

In November the Wisconsin native's ICE completed its acquisition of NYSE Euronext, creating a powerhouse with 16 exchanges worldwide.

22 Avi Reichental

CEO, 3D Systems (DDD)

--Cultural impact

Longtime CEO Reichental is reaping the rewards of the 3-D printing frenzy; revenue for the first nine months of the year climbed more than 40%.

23 Harriet Green

CEO, Thomas Cook Group

--Most Powerful Women
--Turnaround story

Green is wowing once-skeptical investors: The company's stock is up more than 200% for the year -- and 811% since she started in July 2012.

24 Robin Li

Co-founder and CEO, Baidu (BIDU)

--Returnee

China's leading search engine posted strong revenue growth in 2013. Now founder Li must find a way to make mobile search lucrative.

25 Jim Koch

Founder and chairman, Boston Beer (SAM)

--Cultural impact

The independent brewery boosted sales 24% in the first nine months of 2013; founder Koch promotes its Sam Adams beers as affordable luxuries.

26 Kazuki Morishita

CEO, GungHo Online Entertainment

--No. 1 profit gainer
--No. 2 revenue gainer
--No. 1 stock price gainer

Morishita scored big in 2013 with mobile games and teamed up with No. 19 Son to invest in a Finnish gamemaker.

27 Marc Benioff

Founder and CEO, Salesforce.com (CRM)

--Returnee

Cloud evangelist Benioff has been on a buying spree and plans to keep acquiring small companies to help bolster Salesforce's offerings in marketing.

28 Stephen Carley

CEO, Red Robin International (RRGB)

Carley gets plaudits for innovating at the eatery, introducing a popular loyalty program and creating a spinoff build-your-own-burger chain.

29 Jeremy Stoppelman

Co-founder and CEO, Yelp (YELP)

--40 Under 40

The reviews site saw its stock jump 236% this year. Next up: integrating acquisition Qype and securing more small-biz advertising.

30 Carolyn Mccall

CEO, easyJet

--Most Powerful Women
--Turnaround story

McCall has revived the low-cost airline. Shares have soared 60% this year, and in March it joined the U.K.'s FTSE 100 index.

31 James Hughes

CEO, First Solar (FSLR)

The former CEO of energy company AEI is diversifying and turning around the solar-panel maker; the stock has almost doubled this year.

32 Thomas McInerney

CEO, Genworth Financial (GNW)

McInerney is only 11 months into the CEO job but has boosted profits 124% for the first nine months of 2013.

33 Dick Costolo

CEO, Twitter (TWTR)

--Returnee

A glitch-free IPO this fall burnished Costolo's reputation as a manager -- and gave the social network a roughly $25 billion market valuation.

34 Wang Jianlin

Chairman, Dalian Wanda Group

--Cultural impact

The real estate developer with Hollywood dreams -- he bought movie theater chain AMC Entertainment this year -- is now China's richest man.

35 Alan Mulally

CEO, Ford Motor (F)

--Returnee

Ford recently closed its 17th consecutive profitable quarter, and at presstime Mulally's name was on the short list of executives considered to run Microsoft.

36 Michael Corbat

CEO, Citigroup (C)

--Turnaround story

A low-key banker, Corbat pushed Citigroup's recovery by keeping costs in line and introducing new metrics for management performance.

37 Dave Duffield and Aneel Bhusri

Co-founders and co-CEOs, Workday (WDAY)

Bhusri and Duffield have made human-resources software sexy; Workday sales were way up in 2013, and the stock outperformed rival Oracle.

38 Richard Fairbank

Founder and CEO, Capital One Financial (COF)

Those ubiquitous ads paid off: In March, Capital One passed BofA as the fourth-largest auto lender in the nation.

39 Robert Bradway

Chairman and CEO, Amgen (AMGN)

Bradway's experience as a health care investment banker at Morgan Stanley facilitated a smooth $10 billion acquisition of Onyx Pharmaceuticals.

40 Travis Kalanick

Founder and CEO, Uber

--Cultural impact
--40 Under 40

It was a breakout year for Kalanick, whose car service app became a household name. His private company reportedly is valued at $3.4 billion.

41 Carlos Slim

Chairman, Grupo Carso, SAB

--Returnee

Slim's Carso conglomerate saw profits climb, and his mobile company invested in Instagram rival Mobli.

42 James Gorman

Chairman and CEO, Morgan Stanley (MS)

Under Gorman the bank outperformed its peers this year -- and avoided any federal prosecution tied to the financial crisis.

43 Ellen Kullman

Chairman and CEO, DuPont (DD)

--Most Powerful Women
--Returnee

Kullman's recent plans to spin off DuPont's performance chemical business pushed the stock to a 13-year high.

44 Marc Andreessen

Co-founder and general partner, Andreessen Horowitz

--Cultural impact
--Returnee

Silicon Valley's kingmaker scored big on Twitter's IPO.

45 Ken Chenault

Chairman and CEO, American Express (AXP)

--Cultural impact
--Returnee

AmEx is a model for corporations' use of social media, a mandate that comes from Chenault himself.

46 Zhang Xin

Co-CEO, Soho

--Most Powerful Women
--No. 2 profit gainer
--No. 3 revenue gainer

China Beijing's largest developer made headlines in June when she was part of a group that acquired 40% of New York City's iconic GM Building.

47 Tim Cook

CEO, Apple (AAPL)

--Returnee

Apple didn't have a great year, but it remains the world's most valuable company, and most other corporations would kill for its $171 billion in fiscal 2013 sales, up 9%.

48 Severin Schwan

CEO, Roche Group

The Swiss pharma giant's stock outperformed its rivals this year; it recently gained FDA approval for a breakthrough leukemia drug.

49 Patrick Doyle

CEO, Domino's (DPZ)

--Cultural impact

Under Doyle, Domino's has improved its food and bolstered its menu; a new pan pizza now accounts for 20% of Domino's U.S. sales.

50 Jamie Dimon

Chairman and CEO, J.P. Morgan Chase (JPM)

--Returnee

Dimon's had a rough second half, but remember, in early 2013 he survived a proxy fight to strip him of his chairmanship.