It sounds like heresy around here. But here goes:
Is this another tech bubble?
Back East, the Wall Street money is starting to worry that it feels like 1999 all over again. Money-losing technology companies are going public at you've-got-to-be-joking prices. The founders of Snapchat are getting multibillion-dollar offers — and turning them down. And the , a visible symbol of the '90s dot-com boom and bust, is a sneeze away from 4,000, a level it last reached just before, well, you know.
(Read more: The most-overlooked metrics for valuing tech firms)
It this time different? Out in Silicon Valley, many insist it is. But for the average investor, there are reasons for caution.
Since the dark days of 2008, the Nasdaq has risen more than 150 percent, twice as much as the old-school . Money has been pouring into social media stocks. As of Friday, Twitter had risen nearly 60 percent since it went public only a few weeks earlier.
Once again, new "metrics" are being applied to justify stratospheric valuations. Twitter is losing money. A price-to-earnings ratio? There is no E in the P/E. But its stock is trading at 20-odd times the company's annual sales. Good enough.
There is more. Technology companies have become the takeover bait du jour. A report issued by Ernst & Young last week said that mergers and acquisitions in the global technology industry have rebounded to "a new post-dot-com bubble high." Roughly $71 billion in deals were made during the third quarter.
And then there is Kozmo.com, the poster child of the dot-com bust. Kozmo is back. Last time, its couriers would deliver just about anything at any hour — CDs, Milky Way bars, you name it. It burned through $280 million before going bust.
"Remember us?" a banner on the Kozmo.com reads now. "We're relaunching soon."
(Read more: Investors run to Europe for next hot tech start-up)
Many technology entrepreneurs and venture capitalists say there is little to worry about. Which tells you something about bubbles and Silicon Valley. It is difficult to know when any bubble is going to pop until it does. And in Silicon Valley, with its inherent optimism in brighter tomorrows, the view tends to be that the way is always up.
"I'm not going to say there is a bubble or there isn't a bubble," said Naval Ravikant, co-founder of AngelList, a website for raising money for start-ups. "But I lived through the first bubble, and I was in disbelief the entire time, and I don't see anything of that magnitude or scale here today."
Such assurances aside, the numbers are sobering. Eight months ago, Snapchat was valued at $70 million. Today, it is valued at $4 billion, even though it has zero revenue. Six months ago, Pinterest was valued at $2.5 billion. Today, it is valued at $3.8 billion — and no revenue there, either. And last week news broke that Dropbox was said to be seeking a new round of funding that would value the company at $8 billion, up from $4 billion a year ago.
In Silicon Valley, pointing out this sort of thing is considered a bit impolite.
J. William Gurley, a general partner at Benchmark Capital, a big venture capital firm, has scoffed at people who "write silly articles about the notion of a pre-revenue company having a very high valuation."
When the media likened the precipitous decline in the shares of Groupon to the events of the late '90s, venture capitalists went on the offensive.
Michael Arrington, a partner at CrunchFund, wrote on Twitter that The Wall Street Journal was waging a vendetta against the company because it wrote a headline that read: "Groupon Investors Give Up." Chris Dixon, a partner at another venture capital firm, Andreessen Horowitz, joined in on Twitter.
(Read more: Groupon CEO: Our deals are 'designed for mobile')
"Everything is spun negatively," Mr. Dixon wrote. "Comparing current valuations to the dot-com bubble is simply irresponsible."
The venture firm Mr. Dixon joined last year was responsible for $40 million of the $950 million that early investors put into Groupon. But public stockholders have not done well. Groupon's share price has been cut in half in the past two years.
Wall Street is starting to question how long this can all last. A recent Bloomberg survey of Wall Street investors, analysts and traders who use the company's financial data terminals found that the majority thought Internet and social media stocks were at or near unsustainable levels.
Roughly half said that the bubble was here or soon would be.
Not that the big investment houses are shouting sell. They rarely do. As of Friday, 12 of the 17 stock analyst recommendations for Twitter available on Bloomberg terminals were buy or hold. Only five were sell. Of the 48 recommendations for Facebook, 40 were buy and eight were hold. Not a sell to be found.
(Read more: Twitter stock could fall 80%: Hedge fund manager)
Michael Mandel, an economist at the Progressive Policy Institute in Washington who wrote presciently about the '90s dot-com era, said that if there was a bubble this time — and there might be — its bursting would not be as bad as the last one. That is because back then, start-ups advertised on other start-ups' websites and, in many respects, robbed Peter to pay Paul. So when one company collapsed, other dominoes fell, too.
"Bubbles that are not self-feeding are not a big problem, and I'm not seeing the kind of self-feeding that I saw in the '90s," Mr. Mandel said. "So if it turns out that the social media boom is overdone, or that any aspect of the tech economy is overdone, the only thing that will get lost is the money that was invested."
Still, now that companies like Facebook and Twitter are traded on the stock market, the investing public at large is exposed. If big investment institutions pull back from the broad stock market or, worse, start dumping technology shares, everyday investors could get caught in the downdraft.
"What's likely to happen is that there will be a huge winner-takes-all outcome, where one or two companies and investors will be successful," said David Santschi, chief executive at TrimTabs Investment Research in Sausalito, Calif. "But as a result, there will be a lot of companies that are just going to go poof."
And a lot of people's money will go poof with them.