NEW YORK ( Real Money>) -- With Facebook's $100 billion initial public offering coming up later this year, many people are asking: Are we living in another tech bubble?Although there have other companies with frothy IPO valuations such as Linked In ( LNKD) at $9 billion and Groupon ( GRPN) at $11 billion, I would say that those companies are the exceptions and not the rule. We are definitely not yet in a tech bubble. Here's why: 1. The P/E ratios on average are much lower today. As of today, the trailing P/E ratio for the Nasdaq 100 is 11.63. This is down from 13.78 a year ago. At some points in 1999, that ratio was above 100. That means Apple ( AAPL) would have to be trading today with a $5 trillion market cap to equal the market multiple average in the dot-com bubble. 2. The market is still well below the highs of the spring 2000. Back then, the Nasdaq peaked out above 5000. Today, we're excited because we're close to passing 3000 - for the first time since November 2000. 3. The capital raised from tech IPOs is a trickle compared to the bubble years. U.S. tech IPOs raised $8 billion in 2011. In 1999, 289 U.S. tech IPOs raised $24.66 billion. In 2012 dollars, that represents $33.55 billion, which is 4x what was raised last year. 4. The tech window shut for 12 years before recently opening a crack. The IPO window only slightly opened last year for tech companies. It seemed like a flood. However, it's easy to forget that the window had been shut for 11 years before that. 5. Most of the big tech IPOs last year are "broken" -- trading below their first trading price. Demand Media ( DMD) is down 65%. Zipcar ( ZIP) is down 53%. RenRen ( RENN) is down 70%. Boingo Wireless ( WIFI) is down 20%. Yandex ( YNDX) is down 43%. Pandora ( P) is down 27%. Zillow ( Z) is down 12%. HomeAway ( AWAY) is down 35%. Skullcandy ( SKUL) is down 29%. Tudou ( TUDO) is down 37%. GRPN is down 24%. Angie's List ( ANGI) is down 2%. By the way, in the last year, the Nasdaq is up 7.4%. In 1999, IPO companies ended the year 266% above their offer price.