The beginning of the year swoon has decisively been put in the rearview mirror, with the broad-based S&P 500 launching itself to a new all-time high earlier this week on easing geopolitical fears. 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. Dolby Laboratories (NYSE:DLB), for example, has seen its share price rebound nicely since December despite a first-quarter earnings report that lent to modest declines in revenue and adjusted profit. However, investors aren't too concerned with Dolby's past products so much as its bountiful near-field communication patents. NFC technology uses chips to wirelessly communicate payment information between a mobile device and a point-of-sale device. Adoption has been a bit slow, but it's beginning to gain steam, meaning beefed-up royalty payments are likely headed Dolby's way in coming years.

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

Is this viable?
We've been hearing for years that fuel-cell technology could alter how we generate electricity, but like all new technologies, the question of whether it's a viable long-term solution has come into question.

Fuel-cell system providers have been on fire over the past couple months, with FuelCell Energy (NASDAQ:FCEL) completing the world's largest fuel-cell park in February, and more recently with Plug Power (NASDAQ:PLUG) vaulting higher after announcing the order of 1,738 fuel-cell systems to power forklifts at Wal-Mart's regional warehouses. That deal was a catalyst that pushed Plug Power into the serious contender category and also moved its share price up more than 4,600% from its 52-week low.

Today, I'm suggesting that it could be time to cash in your chips on FuelCell Energy until we see more consistency in its order history and a dramatic improvement in its bottom line.

FuelCell Energy's losses have shrunk in each year since 2008, which is a start. But the company has not delivered a profitable year, or even positive free cash flow, over the past decade. Based on data from Morningstar, FuelCell Energy has had a free cash outflow of $534 million over the past decade as its shares outstanding have nearly quadrupled in order for the company to raise cash for research and development and ongoing losses.

Don't get me wrong -- I'm not invalidating fuel-cell systems, because Plug Power looks as if it's come out of nowhere to lead the pack. However, there are companies positioned to achieve profitability faster than others, and FuelCell Energy simply isn't one of those companies. With few big-name contracts currently under its belt, I'd suggest now could be the perfect time to head for the exit.

IP-Oh no!
One possibly telltale sign that the IPO market is nearing a top is the ability to throw a dart and essentially make a double-digit gain overnight. Perhaps no sector has exhibited this more than biotech IPOs which have almost uniformly ascended to the heavens. One I'd consider parting ways with is Revance Therapeutics (NASDAQ:RVNC) which has basically doubled from its public offering price of $16 in just one month.

Like most IPOs, Revance is looking to raise cash for additional clinical studies, and it does have some intriguing offerings in its pipeline. Revance's possible claim to fame is a topical version of botulinum toxin, dubbed RT001, which you may know better by its shorthand, Botox. The topical therapy is being tested in an ongoing phase 3 trial as a treatment for crow's feet lines; a phase 2 trial for patients with hyperhidrosis, a condition in which a person sweats excessively; and a phase 2 trial for migraine headaches. The allure, of course, would be the topical Botox application, rather than injection, which has obvious convenience and pain benefits.

However, when I look at Revance I note it has just two products in its pipeline: RT001 as described above, and RT002, an injectable botulinum toxin candidate for the more precise and localized treatment of glabellar lines. While I haven't seen negative data on either its migraine or glabellar lines studies, they're both extremely early trials that probably shouldn't even be counted on by investors yet. This pretty much leaves RT001 as the ultimate derivation of its value.

In my opinion, Revance is going to have to hope that RT001 is everything that investors are making it out to be since the company is likely to burn through $100 million in total cash over the next two years via clinical studies -- every dime it just raised through its IPO. Even if RT001 is eventually approved, we're probably looking at three or more years, by my own estimate, before Revance is cash-flow breakeven. While I'm not throwing Revance in the gutter by any means, I'd say investors' expectations have far outpaced reality at its current price, and it'll soon enough be looking to raise additional cash, possibly resulting in a dilutive share offering.

Lights out
I have actually been an avid supporter of GT Advanced Technologies (OTC:GTATQ) for more than a year despite the supplier of solar components temporarily ascending to the top of the Nasdaq's list of stocks with the highest amount of short interest.

The thinking behind short-sellers' pessimism had been that China's solar industry was in such dire straits that GT Advanced Technologies, known also as GTAT, would struggle to survive. Being unprofitable, having a glut of supply on the Chinese market, and having tariffs imposed in select countries, the Chinese solar industry seemed headed toward a bad end.

What turned GTAT and the Chinese solar industry around was a pledge by the Chinese government to install 35 gigawatts worth of solar panels by 2015. With many of the country's domestic solar-providers deep in debt, this was one way of ensuring that they would stay busy and perhaps work their way back to profitability. For GTAT, it also meant a surge in orders, as Chinese solar manufacturers reduced their research and development budgets and essentially threw the onus of innovation on GTAT.

While that has worked wonders for GTAT and caused its share price to explode higher by more than 500% over the trailing 52-week period, GTAT is still unprofitable on a trailing basis and valued at 23 times forward earnings.

Despite strong revenue growth potential, GTAT is in a precarious position in China with the government stepping in to support its solar industry. If solar producers do too well they'll simply go back to R&D on their own and cut back on GTAT's solutions. However, even if they do continue to ramp up orders with GTAT, most Chinese solar providers' balance sheets are loaded with debt, making flexibility and expansion difficult, and likely placing an upside ceiling on production capacity. Furthermore, the Chinese government can't support the solar industry by itself, so things could again get choppy for GTAT beyond 2015.

Similar to Revance, I wouldn't consider throwing GTAT in the gutter, but it just doesn't make sense from a valuation standpoint any longer.