Stupidity is contagious -- even respectable companies can catch it. As we do every week, let's take a look at five dumb financial events this week that may make your head spin.

1. 3-D glasses
3-D printing has come under fire this year, and this week 3D Systems (NYSE:DDD) didn't do itself any favors by announcing disappointing preliminary financial results.

The 3-D printing leader -- and now bleeder -- sees adjusted earnings for the current quarter clocking in between $0.83 a share and $0.87 a share. Its earlier guidance called for profitability of at least $0.93 a share. Its earnings guidance for 2014 is also well shy of where the pros were parked.

The stock may have been one of last year's biggest winners, but it has gone on to be one of this year's biggest losers. It has now shed more than 30% of its value through Thursday's close.

2. Pandora panned
Pandora Media (NYSE:P) saw its shares fall 10% on Thursday after posting weak performance metrics for January and offering up a weak guidance for all of 2014.

Pandora served up 1.58 million hours last month, flat with December's showing. Active listeners declined from 76.2 million in December to 73.4 million in January.

The leading music-streaming service is projecting adjusted earnings of $0.13 per share to $0.17 per share this year, short of the $0.19 per share analysts were expecting. Pandora is forecasting $870 million to $890 million in revenue for all of 2014, less than Wall Street's consensus target of $896.3 million.

Pandora's making great strides in monetizing its airplay, but apparently those strides aren't great enough.

3. Hades called -- he wants his stores back 
RadioShack (NYSE: RSH) was a big winner on Super Bowl Sunday with its memorably self-effacing ad drawing attention to its dated image and what it's doing to be relevant on this side of the millennium. However, the retailer's pop on Monday gave way later in the week on reports that it would be closing 500 of its stores.

RadioShack's in a funk, and it's unlikely that a modern makeover will save the chain. Even RadioShack has to know this. Why else would it close hundreds of stores in the middle of a conversion attempt?

4. Tesla goes the extra mile
A team of Tesla Motors (NASDAQ:TSLA) employees set off on a historic journey from Los Angeles to New York using only the electric-car maker's Supercharger charging stations to get around.

Tesla makes the growing network of charging stations complimentary for Tesla owners, making longer treks possible.

The team completed the trek in 76 hours, but there was one notable asterisk. The most direct path from Los Angeles to New York City is less than 2,800 miles, according to Google Maps, yet this trip spanned 3,464.5 miles because of detours to reach the charging stations.

Folks who buy a Tesla Model S likely value the time spent driving out of the way or charging at a station more than the money they are saving with the complimentary charges. The good news on that front is that more charging stations are coming, making this less of an issue in the future. However, if Tesla's going to toot its own horn, we have to point out the shortcomings.

5. Penny lame
Even positive comps aren't enough to save J.C. Penney (OTC:JCPN.Q) these days. The department store operator took a hit after announcing that same-store sales rose 3.1% during the nine-week holiday shopping period in November and December. 

That may not seem too bad, but keep in mind that the stock rallied when J.C. Penney announced that comps in November rose 10.1%. December must've been pretty bad if November's gain averaged with December's results ended in a mere 3.1% advance in comps. 

We don't know how this will play out on the bottom line, but margin-squeezing sales aren't likely to help. Analysts see a sharp loss for the holiday quarter.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.