The broader market may suffer through its tumultuous one- or two-day pullbacks now and then, but the fact that three-out-of-eight stocks are within 10% or less of a fresh 52-week high demonstrates how resilient this market has been. For skeptics like me, that's an opportunity to see whether companies have earned their current valuations.

Source: Donald Lee Pardue, Flickr.

Keep in mind that some companies deserve their valuations. Take railroad operator Union Pacific (NYSE:UNP), which continues to report record results as industrial and agricultural transports increased by double-digits in the first quarter. Even coal shipments stabilized, rising 3% during the quarter. What's more impressive, Union Pacific delivered this growth even with the polar vortex gripping much of the country. In response to its recent achievements, Union Pacific boosted its capital expenditures in an effort to add even more differentiation from its peers. With crude-by-rail a potential area of growth I'd proclaim Union Pacific one company I wouldn't want to stand in front of if I were a short-seller.

Still, other companies might deserve a kick in the pants. Here's a look at three that could be worth selling.

All risk, little reward
All things considered, it's been an exceptionally good year for investors in Questcor Pharmaceuticals (NASDAQ: QCOR), with the shares up nearly 200% from its 52-week low.

The developer of Acthar Gel continues to find new and innovative indications for its product. With 19 approved indications under its belt this one-drug wonder company was able to grow its revenue by 68% in the first quarter to $227.1 million as profits surged 84% to $1.40 per share and total Acthar vials shipped jumped 47% to 7,080.

Questcor investor presentation. Source: Questcor Pharmaceuticals

Of course, the big news that has optimists uncorking the champagne is the proposed purchase of the company by Mallinckrodt (NYSE:MNK) for the combination of $30 in cash per share and 0.897 shares of Mallinckrodt stock for each share of Questcor. Based on Mallinckrodt's closing price earlier this week, this would value Questcor at around $104 per share -- about 10% higher than where it's currently trading. Given that the deal makes sense on paper and Mallinckrodt would see an immediate earnings boost, you might be compelled to believe that this represents an intriguing arbitrage opportunity. I'm here to tell you to consider thinking opposite to that idea and to sell your shares and head for the exit in record speed.

While there's no denying there's limited upside to this deal if it goes through, there are still two gray clouds overhanging this merger that can't be overlooked.

To begin with, although the board members of both companies have agreed to the terms of the deal, neither shareholders from Questcor or Mallinckrodt have voted as of yet. I'd be shocked if Questcor shareholders don't approve the deal, but I wouldn't count on Mallinckrodt's shareholders giving this a slam-dunk approval.

Also, Questcor is currently under investigation for its marketing practices with regard to Acthar Gel. Despite being approved for a number of different indications the price per vial remains constant at $23,000, which apparently caught the attention of regulators. Ultimately, Questcor may have done nothing wrong or it could face a slap on the wrist. Then again, marketing wrongdoings have also been punished with hefty fines as well, which could cloud over Mallinckrodt's bid for the company.

Finally, I've just seen all too often the dangers of investing in a company with a single drug that has multiple indications. If something goes wrong, no matter how mundane, it can disrupt the entire product pipeline. These are all chances that I'm simply not willing to take and which, in my opinion, skew Questcor toward the risk end of the scale rather than the reward end.

Will this company lay an egg for investors?
If you're a short-seller and you've been betting against shell-egg producer Cal-Maine Foods (NASDAQ:CALM), there's a good chance that you have egg on your face at the moment.

Source: Hans, Pixabay.

Cal-Maine has been an unstoppable force of late, with the company scorching higher after reporting strong growth in its fiscal third-quarter results at the end of March. During the quarter it delivered sales growth of 10%, while net income flew 40% higher to $42.9 million, crushing Wall Street's expectations. As noted by Dolph Baker, Cal-Maine's CEO, increased demand for specialty eggs (i.e., organic eggs) really drove demand, as did a sizable improvement in price per dozen and a lowering in feed costs. Combined, these results allowed Cal-Maine to dramatically hike its dividend and leave optimists feeling sunny side up!

But is it possible Cal-Maine could lay an egg for investors following its earnings blowout? I'd suggest that it's almost bound to happen.

Historically, feed costs tend to ebb and flow, much like the market and other commodity based products. In other words, when costs are soaring, you should really consider buying into the Cal-Maine turnaround, and when costs are plummeting, you might consider walking away with your profits in hand. This past quarter saw feed costs per dozen eggs plunge by 16.1% to $0.459 while average selling prices rose to nearly $1.42. There's only so much in the way of cost cutting that can be accomplished by Cal-Maine, so look for that to be a potential sticking point moving forward.

Another key concern here is that unlike specialty food producers, there is absolutely no diversification here. Cal-Maine understands the egg business well, but it is wholly dependent on eggs to drive its growth. If suddenly there's concern about the safety of eggs from one region or country, it could adversely affect Cal-Maine's business. Don't get me wrong, its focus on one aspect of food does help its pricing power as we saw this past quarter, but its lack of diversity is also a crutch in a naturally cyclical industry.

Lastly, where's the growth really going to come from moving forward? Recent acquisitions have helped bump 2014 revenue estimates higher, but the lone estimate on Wall Street currently expects Cal-Maine's top line to contract by 2% in 2015. The third quarter witnessed just 2% more eggs produced than in the prior year period, and consumers probably won't stomach the idea of higher egg prices if gasoline and other consumables are rising too. Long story short, this company could hard-boil hopeful investors if they aren't careful.

Three times the trouble
It's been a while since I spoke of the dangers of triple-levered ETFs, but the consistent rise of the Direxion Daily Technology Bull 3X ETF (NYSEMKT:TECL) is going to prompt me to make it the final addition to today's three stocks near 52-week highs to consider selling.

Source: Kewl, Pixabay

As you might have imagined, with little in the way of correction since the 2009 market bottom the Direxion Daily Technology Bull 3X ETF has been on a tear, rising more than 1,000%. A resurgent U.S. economy, ongoing strength in emerging markets, and an improved U.S. jobs market have all played a role in helping push tech stocks ever higher.

But triple-levered ETFs have one dynamic flaw: daily rebalancing. Unless you can accurately predict the direction the market is headed, these daily rebalancings work against investors over the long run. Not to mention that the increased volatility of these funds, and complete lack of a dividend, ensures that the stockholder won't sleep well at night.

Another worrisome thing to consider is that the Federal Reserve's scaling back of its economic stimulus known as QE3 could put a serious damper on tech stocks. Many have been using record-low lending rates to take on debt at minimal interest cost in order to expand their business. As the Fed scales back QE3 there will be fewer long-term U.S. Treasuries being purchased. Since bond prices and bond yields move in opposite directions, less bond price support may lend to higher yields. If this happens, tech spending may begin to dry up and growth will likely slow. An index like this that's triple-levered to tech stocks could find itself being smacked around if this happens.

Do yourself a favor and leave triple-levered ETFs out of your portfolio.