Kyle Walsh | CNBC

It's early 2019 and you work at one of those richly valued tech companies that's raised billions of dollars on its way to becoming a household name. This is the year it's all supposed to happen for you. You've put in a half-decade or more. You've held onto your stock options even when you could sell a portion, because you believe in the company's mission — or at least the hype. You're poised to cash in when your CEO rings the opening bell at the Nasdaq or New York Stock Exchange, and the six-month lock-up period expires. And by the looks of this year's IPO class, there's a good chance you live in or around San Francisco. San Francisco companies Uber, Lyft and — as of last week — Slack and Postmates have filed confidentially for public listings. Their neighbors Airbnb and Pinterest are expected to follow, though any number of them could get pushed into 2020 if the market turns. Some 2019 IPO plans were already delayed with the month-long shutdown that stalled correspondence with the Securities and Exchange Commission. There's still risk ahead in the form of market volatility, macroeconomic uncertainty and the threat of yet another possible shutdown. But tech stocks are rallying again and big cloud companies are trading near record highs, signaling investor appetite for high-growth names. With the IPO pipeline filling up, there's a ton of money that will likely be unleashed in San Francisco, where the median home value is already $1.4 million, according to Zillow. Among the tens of thousands of employees that work for these pre-IPO companies, a percentage of them will be newly minted millionaires with stock to sell.

Lise Buyer, who advises companies that are prepping to go public, is having flashbacks. She was a tech investor and equity analyst in the late 1990s, when dot-com cash flooded the streets of San Francisco and Silicon Valley. Luxury good sales spiked, charity auctions raked in record cash and resorts were packed. "You couldn't be on the road for 10 minutes without being passed by a Ferrari," said Buyer, who later worked at Google and helped guide its IPO in 2004. "It's not like we're going from zero to 80 in terms of local wealth, but a number of large companies in the same region offering liquidity to large numbers of employees surely has an impact," Buyer said. "You can see it in the restaurants that have changed. You can see it in the car dealerships." One big difference this time around — besides the absence of sock puppets — is the established market for secondary shares that allows employees and early investors to cash out some of their equity early. They haven't been completely tied up waiting for an IPO or acquisition. Uber, Airbnb, Lyft and Pinterest have all enabled employee share sales of one type or another. Larry Albukerk has been busy connecting sellers with eager buyers. Albukerk is founder of EB Exchange, a San Francisco-based firm that helps early employees at start-ups get liquidity. Albukerk said he's seeing more employees and ex-employees with vested shares trying to sell stock now so they can get beat the rush.

Stewart Butterfield, co-founder and chief executive officer of Slack Technologies Inc. at South By Southwest (SXSW) Interactive Festival on Tuesday, March 15, 2016. David Paul Morris | Bloomberg | Getty Images

"I have clients that are stressed out about the pending IPO boom and what it means for them," Albukerk said. "People want to sell ahead of the IPO because they want to buy a house. They feel if I wait for the IPO I'm going to be competing with all these people." Albukerk said he's working with employees from about a dozen companies, including some that are expected to go public this year, but he declined to provide employer names because of confidentiality agreements. "Take all those companies in aggregate and there will be billions of dollars of liquidity for rank-and-file employees that get distributed out to probably thousands of people," Albukerk said. "A lot of it is going to the city."

Companies are older

The housing market in San Francisco has already started to max out, said Daryl Fairweather, chief economist at real estate research firm Redfin. Prices have gotten so high that bidding wars have declined, all-cash offers have become increasingly rare and potential home buyers turned into renters. According to data from Core Logic, sales of Bay Area homes dropped for six straight months last year. "It's not like the flood gates are going to open," Fairweather said. "This is something that is going to happen gradually ... but over time this will heat up the housing market." Suburbs and nearby cities like San Jose and Oakland are also probably going to feel the pinch, she said. That's partly because of the lack of supply in San Francisco, but it also reflects the makeup of the companies, which have mostly been around for close to a decade or more.

Airbnb was founded in 2008, followed a year later by Uber and Slack. Pinterest launched in 2010. Analytics firm Palantir, which is based just south in Palo Alto and is also eyeing an IPO, was founded in 2003. They're not going public with the typical army of 20-something and early 30-something start-up employees, but rather have a workforce of people who are a little older and more likely to settle down and start a family. They'll be looking for "nannies, babysitters ... services and people who can make their lives easier," said Josh Felser, co-founder of venture firm Freestyle. "It would certainly seem like they might potentially crowd out some of the private educational options."

Crowding the Bay Area