Shares of OLED technology expert Universal Display (OLED -2.06%) are plunging today, down 13.4% as of this writing -- no, make that 13.8%. The downward trajectory is pretty clear.

What did the company do to deserve a beating in the middle of Wall Street? Last night's first-quarter report didn't exactly impress.

In raw numbers, this quarter was just fine. Analysts were expecting a net loss of $0.10 per share on roughly $14.4 million in sales. Reported earnings matched that $0.10 target exactly, and sales came in a tad higher at $15.0 million.

But it wasn't a "beat and raise" victory lap. Instead, management simply underscored revenue existing guidance for the just-started fiscal year, ranging from $110 million to $125 million.

That's disappointing due to the simple fact the largest customer Samsung has a hit on its hands with the Galaxy S4 smartphone. The Korean company can hardly make enough components to satisfy global orders, and this OLED-equipped handset is expected to roughly double last year's Galaxy S3 sales.

So, many investors expected Universal's numbers to jump, as the Galaxy S4's success was baked into forecasts. And it didn't happen.

Perhaps this kinda-sorta miss also inspired investors to take a closer look at Universal's fundamental trends. Sales are going through the roof, but profits and cash flows haven't followed suit.

Universal Displays Mixed Messages | Infographics. TTM = trailing 12 months.

As a Universal Display shareholder myself, this is how I'm reading Universal's mixed messages today.

OLED technologies are still in a very early stage of development. Samsung's Galaxy line has sprinkled a few OLED screens across store shelves globally, but mostly in relatively high-end and expensive products with small screens.

Universal Display generally gets paid by the gram of OLED materials, so screen size matters a lot. The real moment of truth comes if and when big-screen OLED TV sets hit the mainstream. Sony introduced a small OLED TV model in 2007; Samsung and LG Display will debut 55-inchers this year. But these are all very expensive, low-volume products. "Mainstream" means mass production and the virtuous cycle of economies of scale. And we're not there yet.

To prepare for that hockey-stick moment, Universal boosted its research and development budget by 33% over the last year. Its phosphorous OLED pixel sales have generally been of the red variety so far, but green emitters contributed a significant slice of this quarter's revenue. The company is also working up better blue and yellow materials, as well as various layers of the OLED screen's materials stack.

Why not build a much stronger product portfolio before your end market really hits the big time? That's what's happening here, and why the bottom line looks so thin. You have to spend money now to make money later. I think I've seen this story somewhere else recently...

Look at that, the stock is down 16% now. Time flies. This volatile stock sure gives investors plenty of opportunities to pick up shares on the cheap.