The Dow Jones Industrial Average (^DJI 0.42%) exhibited all the fears of what the next four years might bring as it tumbled 313 points, or 2.4%, after the results of the presidential election. Naturally financial stocks were crushed by the outcome, but health insurer UnitedHealth Group (UNH 0.30%) fell almost 4% as the only chance for Obamacare's repeal evaporated.

And while there might be a bit of concern about Europe's financial woes wafting through the results, its more worrisome that the political will to forestall the U.S. from turning into Europe is not there.

Yet as bad as things were on the day with the index, the three stocks below did even worse, plummeting by double-digit percentages. Now don't go running over the cliff with them like a bunch of lemmings: it could just be a temporary situation. Let's first see whether they had good reason to fall as panic-fueled routs can sometimes lead to excellent buying opportunities.

Company

% Change

Arch Coal (NYSE: ACI)

(12.5%)

Alpha Natural Resources (NYSE: ANR)

(12.2%)

Universal Display (OLED 2.08%)

(12.1%

The canary just died
Unfortunately it doesn't look good for the coal miners Arch Coal and Alpha Natural Resources. Having a president that wanted to bankrupt any company that built a coal-fired plant reelected to office doesn't bode well for the future. And miners like James River Coal (NASDAQ: JRCC) that are already on a precarious financial cliff of their own find it won't take much to push them over. That's why James River plummeted 30% yesterday, but even the biggest miners like Peabody Energy (BTU) fell 10%.

Some might argue that President Obama is an "all of the above" energy guy since his "Blueprint for a Secure Energy Future" included "clean coal" as one of the facets of what's needed. But that was only added as an afterthought after the industry complained of being left out of the original document. Moreover clean coal isn't the same thing as "dirty" coal because it eliminates the one thing that's really attractive about coal: it's low price. The resource is so plentiful it's dirt cheap, but having to deploy cleaning technology raises the costs of building and running a power plant. That's why no one's really doing it. So talking "clean coal" may make you sound all-inclusive but it's little more than hot air.

There was some hope recently that as the price of natural gas rose again, coal might get a second life. I'd say there's now little hope for an industry resurrection any time soon and investors are likely to find coal stocks only dirtying their hands. I just closed out my outperform rating on Motley Fool CAPS for Alpha Natural, but let me know in the comments section below if Arch Coal, Alpha Natural Resources, or any of the coal miners can survive this collapse in their fortunes.

Fractured future
It wasn't presidential politics that sent OLED developer Universal Display tumbling 12% yesterday, but a surprise earnings loss and the prospects for reduced revenues in the future that depressed the stock and actually sent it tumbling another 27% in extended trading hours.

Organic light emitting diodes may be the wave of the future, with analysts projecting the technology's market share to rise to 16% by 2015, but it won't be straight-line progress as Universal's results show. Instead of the $18.6 million in revenue analysts had been forecasting that would have generated a $0.02 per share profit, the OLED leader recorded a $0.12 per share loss on revenues of just $12.5 million. And that's down from a $0.12 profit a year ago on revenues of almost $22 million.

In September I had reservations about Universal's valuation, noting that LG Display (LPL -2.59%) , which uses Kodak's competing technology, was holding off on ramping up volume production of a 55-inch OLED screen until all the bugs could be worked out. TV shipments have been falling all year long. Yet since Universal supplied Samsung with OLED screens for its Galaxy 3 smartphone, many hoped the popularity of the handset would prop up results.

But Universal didn't receive any payments from Samsung this quarter, and even with $15 million due in the fourth quarter it's still offering guidance well below prior expectations. Management is still hopeful about the future of OLED technology, but it's going to be a longer road to get there. Even with the huge haircut on deck for Universal Display, I don't think it's attractively valued yet, but tell me in the comments below if you feel the stock is now in play.