Yesterday's ADP employment data may not have struck a chord with optimists, and North Korean tensions appear to be escalating, but that didn't stop the S&P 500 from notching two all-time record highs in the past week. For skeptics like me, that's an opportunity to see whether companies have earned their current valuations.

Keep in mind that some companies deserve their current valuations. Health insurer Aetna (AET), for example, hit a 52-week high following word that the Centers for Medicare and Medicaid Services had reversed its original recommendation to cut Medicare Advantage rates and instead favored a 3.3% increase to the reimbursement rates. This move was a key victory for Aetna and the insurance industry, which used its lobbying power to fight back against Obamacare's health-reform initiatives.

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

The waiting game
I'm not a huge fan of short-term underperform calls, but I'm having a hard time getting behind the optimism in Neurocrine Biosciences (NBIX 0.61%) considering that we won't hear anything about Elagolix, its leading experimental treatment for pain associated with endometriosis, until at least the first quarter of next year.

Elagolix turned in fairly impressive results in mid-stage trials, with 86% of patients reporting as "much improved" or "very much improved" under the Patient Global Impression of Change guidelines after a 24-week regimen compared to just 74% for the placebo group. Neurocrine even received a nice bump in the form of collaborative revenue from its Elagolix licensing partner AbbVie (ABBV 0.76%) in the fourth quarter, reporting a profit of $0.14 when a loss was expected by the Street. 

But what this comes down to is that Neurocrine has no drugs currently approved by the Food and Drug Administration, and it's likely to burn in the neighborhood of $50 million to $55 million in cash this year. Even if Neurocrine delivers favorable results from its phase 3 trial on Elagolix in the first half of 2014, it still has a second trial to finish. Data from that trial won't be available until 2016, which is likely the same year we'd see an FDA approval for Elagolix, meaning the chance of a profit is still about a half-decade away! While I'm not gung-ho negative on Neurocrine because of its mid-stage data, its current $800 million valuation just doesn't seem justified with so few near-term catalysts.

Sprechen sie sell?
Language software developer Rosetta Stone (RST) must be doing something right, because its whispers of sweet nothings into the ears of shareholders have sent its stock roaring higher by 36% since the end of February. A change in its CEO last year, coupled with a drastic reduction in costs heralded by the closing of more than half its in-mall kiosks, helped drive profits in the near term. But the long-term outlook for Rosetta Stone still looks dreary at best.

To begin with, where on earth is the revenue growth going to come from? Fellow Fool Rich Smith astutely points out that Rosetta Stone's $8.5 million purchase of Livemocha will bring 16 million new customers into the fold, but not all of these customers pay for the service. Good luck converting those members, Rosetta Stone!

If you look overseas, growth has been dreadful. International bookings dropped 29% in the fourth quarter because of weakness in Japan and Germany. The company is basically winding down its in-person presence in many locations and replacing it with an online-only presence, which will save costs, but not necessarily boost sales.

Rosetta Stone plans to rely on its products' innovation to drive growth, but I contend that its previous innovations with an in-store presence weren't driving rapid growth to begin with. At 56 times forward earnings, I'm suggesting you say "nyet" to buying Rosetta Stone.

Three times the danger
Every few weeks I scour the list of new highs, and every few weeks I'm flabbergasted by the number of Direxion triple-levered ETFs that are sitting near a new high.

This week, the Direxion Daily Real Estate Bull 3x (DRN 0.65%) is clear in my crosshairs following a phenomenal 500% run over the previous four years. It's not that I don't believe the housing and commercial rental sector is slowly improving -- since this ETF tracks MSCI REIT index to a factor of three -- but the scale by which investors expect the REIT environment to continue to improve just isn't reasonable. It has taken an exceptionally strong move upward in the MSCI REIT index to provide investors with these returns, and I highly doubt it will be able to keep up this pace. 

Another factor that often gets overlooked with triple-levered funds is that even when the underlying index provides flat returns, daily rebalancing can work against investors. Even with its amazing returns, this is yet another highly levered fund I would suggest leaving on the shelf.

Foolish roundup
Nothing would describe this week's theme better than "Really?" I feel Neurocrine's lack of near-term catalysts, Rosetta Stone's lack of sales growth, and a projected inability for Direxion's Real Estate 3x Bull ETF to keep up its impressive returns thus far all provide more than ample reason to avoid all three stocks.

I'm so confident in my three calls that I plan to make a CAPScall of underperform on each one. The question is: Would you do the same?

Editor's note: A previous version of this article incorrectly stated that Livemocha's customers pay no fees to use the service. We regret the error.