With no domestic economic news on the docket, the broad-based S&P 500 (SNPINDEX:^GSPC) took its early cues from the Shanghai Composite which fell nearly 3% overnight following abysmal Chinese export data.

Overseas shipments from China dipped 18.1% in February, which looks even worse when compared to analyst forecasts for an expansion of 7.5%! The Chinese New Year certainly makes visibility difficult for economists sometimes, but we're talking about a better than 25% miss here that could signal the Chinese economy is weakening. That's not even in the ballpark, and it's one reason why the markets headed decisively lower in the early morning.

By day's end, however, the S&P 500 had recouped much of its losses as the situation in Ukraine, which is a daily geopolitical hot spot now, had not worsened, and what select earnings reports were out there trended toward better than expected.

The S&P 500 finished lower by just 0.87 points (-0.05%) to close at 1,877.17, which is much better than its earlier intraday low of 1,867.

One of the day's biggest gainers was small-cap clinical-stage biopharmaceutical company Northwest Biotherapeutics (NASDAQ:NWBO), which gained 29.6% after Germany granted its experimental immunotherapy DCVax-L two special approvals. The first approval, from Germany's equivalent of the U.S. Food and Drug Administration, is a five-year-term "hospital exemption" that allows German hospitals to use DCVax-L in treating newly diagnosed and recurrent glioma brain cancers. This exemption will allow Northwest Biotherapeutics to charge full price for its treatment outside of its ongoing U.S. clinical trials.

In addition, the German reimbursement authority made DCVax-L eligible for health insurance reimbursement in the nation. A press release noted that six hospitals have applied for reimbursement eligibility thus far. This is clearly good news for Northwest Biotherapeutics and could go a long way toward validating its immunotherapy platform. However, I'd keep in mind that this is but one country, and its success in the U.S. via ongoing phase 3 studies is far more crucial. Investors should not get carried away by chasing today's news too much higher.

The S&P 500 standouts, though, once again were fuel-cell system developers Plug Power (NASDAQ:PLUG), which gained 24.7%, and Ballard Power Systems (NASDAQ:BLDP), which claimed top honors with a 30.3% daily gain. What's really interesting is that neither move had any company-specific news behind it today, with both stocks feeding off of optimism from last week.

For Plug Power, that continues to be the bullishness surrounding its order to supply 1,738 fuel-cell systems for forklifts in select Wal-Mart warehouses throughout the U.S. The thinking from investors here is that a large client such as Wal-Mart could open a number of doors for Plug Power to gain new contracts, and could even remove some of the lumpiness with its revenue stream that shareholders have become accustomed to over the years.

Ballard Power Systems shareholders seem most excited by the fact that nearly 5 million warrants were exercised last week related to two 2013 underwritten share offerings. These warrants helped to generate $7.6 million in additional funds for Ballard, which it can use for general corporate purposes, as well as research and development.

The key point to note here is that both Plug Power and Ballard Power Systems are losing money. Plug may have snagged itself an elephant in Wal-Mart, but with a $1.1 billion valuation and the expectation of perhaps $60 million in revenue in fiscal 2014, the move may be a bit excessive. The same could be said for Ballard Power which is closing in on an earnings-per-share breakeven point (likely by 2016), but is valued at close to eight times next year's revenue. This looks like a sector that could deflate any day.

Fuel-cell developers are soaring, but even they may be no match for this top stock in 2014
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Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.

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