The biggest cloud news last week was the Amazon Web Services outage, and it has many doubting the security and reliability of the IaaS model. All the same, the Talkin' Cloud Stock Index rose 1.79 percent for the week ending April 22, 2011 -- though the fact that Amazon's cloud likely won't be up to full functionality by the time the market opens on Monday may start this week off on the wrong foot. Here's our weekly look at the winners and losers among the 20 cloud and SaaS providers that make up the index.

Before we dive in, let's go over some basics: We maintain the Talkin' Cloud Stock Index to match cloud hype against real-world performance. We're not financial advisors, and whether you buy, sell or hold is up to you. And, some housekeeping: Verizon completed the Terremark acquisition and Time Warner completed the NaviSite acquisition, so both NaviSite and Terremark will be replaced in our index, effective this week.

The Winner's Circle

  • Virtualization specialist VMware (VMW) saw the biggest boost of the week, gaining a strong 12.58 percent to $96.81 per share on the back of a very positive Q1 earnings report.

  • SaaS employee management solution vendor Kenexa (KNXA) rose 8.04 percent to $29.70/share after garnering some analyst interest for its solid performance this year.

  • It seems that CRM provider (CRM) was able to turn the success of customer Fireclay Tile into a 4.59 percent gain to a stock price of $139.87. Apparently, the hype around using the cloud to grow a company even in a sputtering economy was enough to garner some investor confidence.

  • Rackspace Hosting (RAX) rose 3.93 percent to $44.69/share before the U.S. markets closed for the long Easter holiday weekend. The reasons aren't immediately apparent, but as some analysts note, its strengths can be seen in multiple areas such as its robust revenue growth, impressive record of earnings-per-share growth and compelling growth in net income.

And The Rest

  • Somewhat surprisingly, wasn't the biggest loser of the week. That dubious honor goes instead to SaaS marketing provider Constant Contact (CTCT), which fell 5.79 percent to $31.09 per share after analysts failed to reach consensus on whether the company was a "buy" or a "hold."

  • (AMZN) showed a dip of 3.17 percent to $174.31 per share. It looks like the impact of Amazon EC2's ongoing failure was mitigated somewhat by the retail division's public confidence that the company can weather the controversy around charging sales tax. And needless to say, no matter how popular Amazon Web Services gets, e-retail is still the company's bread-and-butter.

  • Vocus (VOCS), which specializes in PR management, dropped just 2.83 percent to $25.07 per share. Again, reasons for this downward move aren't obvious. But it has been on the wrong side of a slippery slope for a few weeks now.

I'm no stock market wizard, but I know that growth is better than shrinkage. All the same, it would nice if we could see some double-digit weekly growth. But with Amazon Web Services' problems and the Sony PlayStation Network still down under hacker assault, it doesn't seem very likely anytime soon.

Follow Talkin’ Cloud via RSS, Facebook and Twitter. Sign up for Talkin’ Cloud’s Weekly Newsletter, Webcasts and Resource Center. Read our editorial disclosures here.