Employees at Sunnyvale's Ruckus Wireless greeted Friday morning with champagne, as the maker of Wi-Fi technology went public after an eight-year run-up. But by the time the stock markets closed, they may have been reaching for the hard stuff.

On a day the broader markets finished up slightly, Ruckus -- trading on the New York Stock Exchange under the symbol RKUS -- saw its stock plunge 18 percent below its $15 initial offering price. It closed at $12.25.

Some pundits were quick to accuse company management of overreaching by setting the price at the top of its range, even as the markets have wobbled amid investor worry about the U.S. economy.

"When the market's down, there's less interest in IPOs, and people are concerned about valuations," said Francis Gaskins, president of IPOdesktop.com in Marina del Rey.

Ruckus Chief Executive Selina Lo, in an interview from the NYSE floor, acknowledged that she'd thought about postponing the IPO, as did three other companies that were scheduled to go public this week.

But she said investor interest had been strong during roadshow meetings, even amid the soft market: The company raised $126 million through the offering, selling 8.4 million shares.

Lo rang the NYSE opening bell as part of a debut that included Ruckus banners hung from the building's facade and stuffed versions of the company's dog mascot passed out amid bemused traders.

And, like many of the employees who watched the morning festivities on a big-screen TV in company headquarters, she insisted that the stock's one-day performance -- good or bad -- was only one step on a long journey.

"This isn't just about one day," Lo said.

Nothing's come easy for Lo or her company, which despite more than $70 million in private capital from investors, including Sequoia Capital and Motorola, has been forced to shift business models several times.

Founded in 2004, Ruckus makes "smart" Wi-Fi antenna arrays that can send wireless signals in any direction, reducing interference. The company initially focused on distributing wireless TV but found consumer demand wasn't robust enough to spur meaningful growth.

Ruckus switched focus, selling big corporate clients including hotels on Wi-Fi hot spots; its success in that market started to catch the interest of Internet service providers. Ruckus now claims 16,000 customers, most of them overseas, and last year posted a $4 million profit.

"You feel very proud when you overcome the rough times," said Gilbert Phong, an engineer who was the eighth person hired at Ruckus. The company currently has more than 600 employees, a third of whom work in its new headquarters in Sunnyvale.

Phong said he'd weathered the uncertainty of an unusually long startup incubation period in large part through his faith in the hard-charging Lo, with whom he'd worked at Alteon WebSystems. The San Jose networking equipment maker was sold to Nortel for $7.8 billion during the dot-com bubble.

As Phong spoke, his co-workers enjoyed a hot buffet of French toast, honey-cured bacon and made-to-order omelets. Most wore T-shirts that read, "Occupy Wall St., Ruckus Style."

Lo becomes just the third female CEO of a Silicon Valley-based public company, and one of only a handful of Asian-American women nationwide to hold such a post. Only two companies in the Fortune 500 -- neither of them tech companies -- are led by Asian women.

The good news for companies like Ruckus is that, thanks to the iPhone, iPad and Android devices, demand for mobile content is exploding, said Will Power, a wireless industry analyst with R.W. Baird in Dallas.

"On the other hand," he said, "telecom equipment generally remains a viciously competitive environment." Ruckus competes with the likes of Cisco Systems (CSCO), Meru Networks and Aruba Networks, all of which are publicly traded.

Gaskins, the IPO analyst, noted that while Ruckus reported that its revenues, at $144 million, nearly doubled over the first nine months of this year compared with 2011, the $15 share price was still 81 times earnings.

"That's really high, even for a high-growth company," he said.

And, he added, given Friday's underwhelming debut, the company will have to reassure investors with "another two good quarters, or they're just gonna get hammered."

Staff writer Jeremy C. Owens contributed to this report. Contact Peter Delevett at 408-271-3638. Follow him at Twitter.com/mercwiretap.

ruckus wireless
Founded: In 2002 as Sceos Technologies; later changed name to Video54 before relaunching as Ruckus in 2004
Headquartered: Sunnyvale (where it recently moved into a 155,000-square-foot building)
What it does: Sells "smart Wi-Fi" antenna arrays that use software to reroute wireless signals to reduce interference
Customers: Include Time Warner Cable and large mobile carriers, who use Ruckus devices mounted on telephone poles and rooftops to shift traffic from 3G cellular networks to Wi-Fi during heavy usage. During the Democratic National Convention in Charlotte, N.C., Ruckus antennas helped manage a crush of cellphone and wireless data traffic.
Source: Ruckus Wireless