Private company valuations for security companies are up, but venture investors remain excited about putting to money to work. There is no secret why. Governments and corporations are under attack from cyber hacks, and IT budgets are being freed up for products and services to strengthened digital defenses.

Last year security investing rose 5% to $1.02 billion at a time when venture investing overall fell 10%. The increase came after a hefty 94% jump in venture dollars committed in 2011.

With nearly 11 months in the record books, 2012 stands out as the year of the enterprise and IT-related venture-backed IPO. Enterprise- and IT-related deals make up 40% of this year’s venture-funded initial public offerings, according to a peHUB analysis.

Across Silicon Valley, people are getting rich through sales and IPOs of startups in the social media and software sectors. But they’re not getting as rich as they thought they would, so they’re being more careful about how they spend their money, wealth advisors say.

At long last we’re getting ready for Facebook’s IPO later this month. So who else from the latest bumper crop of IPO candidates has some impressive results to boast?

Trending on peHUB this week: Splunk, Infoblox, Proofpoint, Sequoia Capital, Sevin Rosen, Mohr Davidow, Thrivent, Spectrum Equity, SurveyMonkey, New Mountain Capital, UTIMCO, Union Square Ventures, True Ventures, King.com

Big data software maker Splunk floated shares at $17 this morning, and they are presently trading at $32.01, an 88.3% rise. The San Francisco company priced them above its anticipated $11 to $13 range and raised $229.5 million.

Forget Facebook. The fate of the IPO market this week could depend on the public offerings of three lower profile enterprise companies backed by venture firms: Splunk, Infoblox and Proofpoint.

In a week of hot IPO news, Splunk–looking to sell at $8-$10 per share–is ready to lead off.

Four of the five companies have collectively raised more than $460 million in venture capital from firms including Greylock Partners, Sequoia Capital and Technology Crossover Ventures.