Today: Zendesk pricing and first-day pop show strength, which could prompt Box and others to make the IPO leap. Also: Wall Street plummets, but Cisco gains.

The Lead: Zendesk jumps in first trading day, are more to come?

Silicon Valley technology companies that have prepared for initial public offerings have stayed on the sidelines as tech stocks have been bludgeoned on Wall Street over the past two months, but the performance of San Francisco's Zendesk could bring an end to that trend.

The cloud-software company priced its IPO at $9, the middle of its proposed range, on Wednesday evening, a victory in itself after a run of IPOs that priced at the bottom of their ranges or lower. After reaching Wall Street on Thursday morning, Zendesk shares shot as high as $13.92 and never traded lower than $11; the stock closed at $13.43, a 49.2 percent first-day pop that should give confidence to the rest of the Silicon Valley pipeline.

"Zendesk is a fantastic company, and you need a fantastic company to reopen the market," Venky Ganesan, a managing director at venture firm Menlo Ventures, told the Mercury News.

"A month ago it was growth at all costs, and now it's growth with a path to profitability," Ganesan, who is not a Zendesk investor, said.

As Wall Street has driven tech stock prices down, with depreciation especially prevalent among companies that recently went public, several Silicon Valley companies that planned IPOs have reportedly backed off those plans. The most prominent on the list, Los Altos-based Box, conceivably could have gone to market last month and was reportedly planning to sell shares this month before changing its mind.

"Our IPO has never had a set date," a Box spokesman told the Mercury News earlier this month. "Since filing, we've planned on going when it makes the most sense for the market. That plan hasn't changed."

Mountain View's Mobile Iron, which was joined in the pipeline by Sunnyvale rival Good Technology on Wednesday, and Arista Networks also reportedly delayed their first stock issuances this month. That plan seems to be smart: Venture capitalists turned their attention from young startups to more established private companies in the first quarter, giving firms an easier route to the cash they need to scale a winning idea to an established company.

That path has given Silicon Valley tech companies a cash cushion that allows them to avoid going public out of pure need for cash, an untenable position that can lead to a smaller cash haul. It has also allowed for record valuations, the latest evidence of which arrived Thursday afternoon, when Bloomberg News reported that San Francisco transportation app Uber is shooting for a $10 billion valuation in its next round of financing, which would tie records recently set by AirBnB and Dropbox.

Despite the riches that can be had in private financing, though, the public markets are still a draw, and the IPO market is still attracting Silicon Valley tech companies that could be hitting Wall Street soon.

"There's still an appetite," Brent Gledhill, global head of investment banking for William Blair, said. "We still see IPOs being successful. We're still getting them done. There's just a higher bar."

SV150 market report: Wall Street plunges, Cisco gains after earnings

Wall Street suffered as Zendesk prospered Thursday, as the Dow Jones industrial average had its largest one-day drop in more than a month. Silicon Valley tech stocks outperformed the overall market, though, thanks to a strong post-earnings performance from Cisco Systems.

The San Jose networking giant posted earnings that easily beat expectations Wednesday afternoon, despite experiencing a retreat from the same quarter a year ago. Analysts bumped up price targets and future earnings estimates after getting a look at Cisco's results, with FBN Securities analyst Shebly Seyrafi writing, "The bottom line: Cisco is through the worst and has stabilized its business." Cisco shares gained 6 percent to $24.18 Thursday, despite pictures that claimed to show the NSA planting bugs in Cisco hardware bound for customers in other nations, which the company vehemently denied knowledge of.

Applied Materials joined the earnings parade Thursday, reporting net income of $262 million, or 21 cents a share, on sales of $2.35 billion, both substantial gains from the same quarter last year; after closing with a 4 percent decline at $18.698, Applied Materials stock jumped to more than $19.30 in late trading. Gilead Sciences lost 1.1 percent to $80.10 despite a federal agency suggesting that those at risk of contracting HIV take a medication offered only by the Foster City biopharmaceutical company, which the New York Times reports could boost prescriptions for the drug, Truvada, from 10,000 to more than 500,000. Workday declined 0.4 percent to $70.69 after the Pleasanton cloud software company announced that its co-founders would no longer be co-CEOs, with Dave Duffield becoming chairman and Aneel Bhusri taking over as CEO. eBay dropped 0.6 percent to $51.36 while continuing to revamp PayPal and launching Spanish- and Portuguese-language versions of its main website, and Yahoo declined 1.1 percent to $33.80 as former board member Dan Loeb dropped the rest of his shares in the Sunnyvale company.

Up: Cisco, Symantec, LinkedIn, Yelp, Juniper, NetApp, VMware, Oracle, Pandora

Down: SolarCity, Zynga, SunPower, Facebook, Netflix, SanDisk, Hewlett-Packard, Applied Materials, Intel, Intuit, Adobe, Yahoo, Gilead, Tesla, Electronic Arts, Google

The SV150 index of Silicon Valley's largest tech companies: Down 6.73, or 0.48 percent, to 1,384.83

The tech-heavy Nasdaq composite index: Down 31.33, or 0.76 percent, to 4,069.29

The blue chip Dow Jones industrial average: Down 167.16, or 1.01 percent, to 16,446.81

And the widely watched Standard & Poor's 500 index: Down 17.68, or 0.94 percent, to 1,870.85

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