Stupidity is contagious. It gets us all from time to time. Even respectable companies can catch it. As I do every week, let's take a look at five dumb financial events this week that may make your head spin.

1. Sony is more bony than tony
Sony (NYSE:SNE) is celebrating the 30th anniversary of the Sony Walkman this week. Unfortunately, it's not going to like what it sees when it blows out the candles. Where have you gone, Walkman? Heck, where have you gone, PS3?

It seems as if every child of the 1980s grew up with a Walkman. Cassettes yielded to CDs. CDs handed the baton to digital delivery. Where is Sony now? It could have been the leader in digital media players. Instead of Apple's (NASDAQ:AAPL) iPod, we should be cranking up the Sony iWalkman. We could be downloading content from Sony, which makes sense because Sony already owns a major movie studio and one of the four major labels.

Unfortunately, Sony fumbled away its market dominance. You don't have to even go 30 years to see Sony repeat its mistake. Sony's PlayStation was once the video game platform of choice. These days, the PS3 is a laggard and losing developer support.

So, who is in the mood to celebrate when Sony is coming off its first annual loss in over a decade? Don't get me started on the chatter over a PSP-based smartphone. It's too little, too late from a company that peaked too soon.

2. Now with nearly 30% real banana
You can't blame Starbucks (NASDAQ:SBUX) for trying. The barren barista baron is hoping to jump-start its disintegrating comps with a healthier menu that centers around natural ingredients. The items include a 210-calorie Marshmallow Dream Bar and a slice of banana walnut bread that "is nearly 30 percent real banana."

You may be applauding the move, but I'm shaking my head. Turning to organic Michigan blueberries for its blueberry oat bar may win it style points, but it's not going to win back the long lines it used to command several years ago.

The prevailing bullish argument that Starbucks sells a reasonably priced cup of coffee is fair, but it's still an incremental expense for java junkies who now have cheaper -- and occasionally more convenient -- access to premium bean brews.

Starbucks isn't going to bounce back until it makes a serious dent at meal replacement in the breakfast, lunch, and dinner markets. I don't think a barista-tossed salad or a blended fruit smoothie is going to make "who wants to join me for lunch at Starbucks" a popular water cooler query. 

3. Hong Kong phooey
Disney (NYSE:DIS) is finally digging deep into its pockets to fix the moribund Hong Kong Disneyland attraction that it opened, with financial assistance from the Hong Kong government, nearly four years ago.

Disney will be investing roughly $450 million in new themed lands and rides for its gated attraction. In exchange for the necessary infusion, Disney's stake in the park will grow from 43% to 48%. Hong Kong owns the rest.

This is the right move, but it lands the family entertainment giant into the "dumbest stock moves" list because it took so long to address the park's shortcomings. Disney conservatively projected that the park would draw 5.6 million guests in its first year. It only drew 5.2 million. Things got even worse in the second year, attracting a mere 4 million parkgoers. It should not have taken Disney -- and the Hong Kong government -- this long to realize that the park just wasn't appealing enough in its original incarnation.

4. Too big to succeed?
Oracle's (NASDAQ:ORCL) Larry Ellison may finally be ready to check into Overeaters Anonymous. Regulators are requesting more time to review the software giant's planned purchase of Sun Microsystems (NASDAQ:JAVA).

Ellison knows the drill. He's a serial acquirer, so he knows all about the paperwork you have to fill in as you wait your turn in the Vegas wedding chapel. He's had deals delayed before, but he usually gets his company.

Has Oracle finally eaten too much? Is it finally too big for anything but organic growth? It will be a sad day when Ellison isn't snapping up smaller tech stocks, but it may be coming sooner than we think.

5. Quoth the Maven nevermore
Yahoo! (NASDAQ:YHOO) paid roughly $160 million to buy online video syndicator Maven Networks last year. Now it is shutting down the service and winding down the existing contracts on the platform.

Doesn't Yahoo! want to grow its reach, especially when it comes to Web-based video? Yahoo! isn't very patient with its own properties, but you would think it would have a little more tolerance when it forks over nine figures for an upstart.

Let's beat the dumb drum:

Apple, Walt Disney, and Starbucks are Motley Fool Stock Advisor recommendations. The Fool owns shares of Starbucks. Starbucks and Disney are Motley Fool Inside Value selections. Try any of our Foolish newsletter services, free for 30 days.

Longtime Fool contributor Rick Munarriz is a fan of dumb and smart business moves. Investors can learn plenty from both. He does not own shares in any of the stocks in this story, save for Disney. Rick is also part of the Rule Breakers newsletter research team, seeking out tomorrow's ultimate growth stocks a day early. The Fool has a disclosure policy.