SUN VALLEY, Idaho — After a year of mixed initial public offerings and continuing disruptions in the media industry and the broader global economy, a cloud of uncertainty hangs over this year's Allen & Co.'s annual conference, aka the summer camp for moguls.

Last year, the industry was busy toasting the new Web kings — a group led by Mark Pincus, the chief executive of Zynga; Andrew Mason, the chief executive of Groupon; and Mark Zuckerberg, the head of Facebook, who brought his playful Puli, Beast. At the time, their companies were on the verge of going public at sky-high valuations.

And while many technology hotshots are back, their golden glow has faded. In the months since, the startups have received a swift lesson on the capricious nature of the public markets.

Zynga, the game maker, is about 50 percent below its offering price. Groupon is trading below $8, a record low. Facebook, after a tumultuous first month, has clawed its way back but is still 18 percent below its offering price. The pain in the public markets has seeped into still-private companies, damping enthusiasm for other prominent startups like Twitter, the microblogging service.

At least one technology powerhouse, however, has managed to hold its weight.

Amid all the big names, Tim Cook, chief executive of Apple, has been a magnet for moguls here. His predecessor, Steve Jobs, was never a Sun Valley fixture. Apple, known for its secrecy, has generally been a no-show. That makes Cook's attendance notable in itself.

On Wednesday, Cook tried to keep a low profile, although he has lined up several one-on-one meetings, fueling speculation that he is busy cobbling together partnerships for the next-generation Apple TV. Wearing a blue button-down shirt and jeans, he walked briskly past the photographer pit with Paul Sagan, chief executive of Akamai, the Internet content delivery service.

When asked what he was looking forward to at the conference, Cook demurred.

"I'm looking forward to all the private discussions I've set up this week," he said.

Amazon.com CEO Jeff Bezos was seen walking to a morning session Thursday chatting with author and former NBC anchor Tom Brokaw.

There has been a power shift at the Sun Valley conference, hosted by the boutique investment firm.

Tensions remain between media and technology companies over the distribution of content via digital platforms. But in the past year, media executives have said they feel more positive about harnessing new media as a means to build additional revenue sources.

Some attendees also expressed relief that the technology executives — once seen as infallible, with the keys to the media industry's future — have been taken down a peg. Indeed, many media executives strolled in this week with a spring in their step.

At the Duchin Lounge on Tuesday night, a small group of technology and media moguls took advantage of the opportunity to mingle and informally discuss potential partnerships. Mark Pincus and Eric Lefkofsky, the co-founder of Groupon, made quick visits before retiring to their rooms. (Mason of Groupon, joined at the hip to Lefkofsky last year, was noticeably absent.) Jack Dorsey, the co-founder of Twitter and Square, held court with a small group outside. After a late entrance, Zuckerberg also showed up, alongside his friend Drew Houston, the chief of Dropbox. Clad in a gray shirt and jeans, Zuckerberg made a quick beeline for the lounge.

Politicians, business leaders and philanthropists are also among the prominent attendees this week. New York City Mayor Michael Bloomberg arrived with former city schools chancellor Joel Klein (now chief executive of News Corp.'s newly formed education division) and Cory Booker, the Democratic mayor of Newark, N.J.

Kazuo Hirai, the recently named chief executive of Sony, rushed past reporters as his predecessor, Howard Stringer, lingered in the lobby. Filmmaker Harvey Weinstein also made a brief appearance.

Although it is unclear if any big deals will get done in Sun Valley, the moguls seemed optimistic that Sun Valley was at least ripe for productive discussions.

Time Warner's chief, Jeffrey Bewkes, who once compared Netflix with the Albanian army taking over the world, said he had already chatted with the Netflix leader, Reed Hastings, at the conference, with more discussions planned during the week.