Welcome to Week 31 of the Big Idea Portfolio. This week, investors once again chose to believe in Apple (Nasdaq: AAPL) even as they showed signs of losing faith in salesforce.com (NYSE: CRM). More of what's going on in my portfolio, and more tech stock news, in a minute. First, let's dig into the numbers:

Company

Starting Price*

Recent Price

Total Return

Apple $422.46 $615.70 45.7%
Google $650.09 $641.33 (1.3%)
Rackspace Hosting $41.65 $45.25 8.6%
Riverbed Technology $25.95 $17.87 (31.1%)
Salesforce.com $100.93 $128.27 27.1%
AVERAGE RETURN -- -- 9.80%
S&P 500 SPDR $126.50** $139.35 10.16%
DIFFERENCE -- -- (0.36)

Source: Yahoo! Finance.
* Tracking began at market close on Jan. 6, 2012.
** Adjusted for dividends and other returns of capital.

The week that was
Make that three consecutive weeks of gains. For the most part, anyway. A huge Friday rally lifted all but the small-cap Russell 2000 index, which closed off 0.94%, into the black for the week. The S&P 500 led the leaders with a 0.36% gain ,followed closely by the tech-heavy Nasdaq, which closed up 0.33%. The Dow also eked out a gain, closing up 0.16%, according to data supplied by The Wall Street Journal.

Credit a good employment report for the weekly win. A new government report shows the U.S. economy added 163,000 jobs in July, a major improvement over June's largely disappointing figure. The hiring figures more than compensated for disappointment over the Federal Reserve's decision to hold off on any new stimulus efforts. Fed members met Wednesday and are due to convene again later this month at the Fed's annual symposium in Jackson Hole, Wyo.

Volatility may also have kept a lid on stock prices. In a trading glitch that now appears to have cost Knight Capital Group (NYSE: KCG) roughly $440 million in losses, some 150 New York Stock Exchange-listed equities fell to uncommon lows on Wednesday.

We're still learning all that went wrong. What we know for sure is that Knight, which serves as bridge between retail brokerages and large banks, helps investors execute billions of dollars' worth of equity trades each day. According to Bloomberg News, the firm is in talks with Goldman Sachs about a potential rescue package.

Tech poppers and floppers
For all that went wrong last week, plenty also went right. Apple rallied on renewed faith in the business that seems entirely justified. Consider the strength of the iPad business. Amazon.com introduced a new iPad app that allows users to play purchases made from the e-tailer's library of titles. Members of the Prime premium shipping service are also eligible to freely stream any number of thousands of available videos.

Meanwhile, salesforce.com is suffering from what appear to be self-inflicted wounds. The maker of cloud-hosted business management software suffered two major outages in July. On Aug. 1, email service slowed for as-yet unidentified reasons. While this is hardly the first time salesforce.com has endured system issues -- all Internet services have at some point -- investors can hardly be blamed for getting nervous. Cloud computing services are only as good as they are durable.

Finally, in earnings news, LinkedIn (NYSE: LNKD) soared 16% after an 89% revenue increase beat analyst forecasts. Earnings came in at $0.16 a share, matching estimates. Activision Blizzard (Nasdaq: ATVI) also put up a big performance. The gaming specialist produced better-than-expected revenue and earnings in its fiscal fourth quarter and raised guidance on hopes for the upcoming release of Diablo III.

Did your stocks beat the Street? Did they come up short? How so, and what's your next move? Use the comments box below to explain your thinking.

And see you back here over the weekend for more tech-stock talk. In the meantime, keep track of all Apple's moves and their impact on investors with this special report outlining the risks and opportunities facing the business. It comes with a full year of free updates, so make sure to get your copy now. Also, don't forget to add the Big Idea portfolio stocks to your Foolish Watchlist for ongoing, up-to-the-minute coverage. Both the report and the Watchlist as 100% free to Fools: