Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

Shares of LED supplier Universal Display (Nasdaq: PANL  ) plummeted 18% today after its quarterly results and guidance missed Wall Street expectations.

The company's third-quarter miss was so wide -- EPS loss of $0.12 on revenue of $12.5 million versus Wall Street's estimate of a $0.02 profit and a top-line of $18.6 million -- that analysts have no choice but to lower their valuation estimates yet again. Management cited weaker materials sales and license fees for the miss, reinforcing serious concerns over a prolonged slowdown in the industry.

Management now sees full-year revenue of $80 million-$82 million, down from its prior view of $90 million-$110 million and well below the consensus of $100 million. "We have never taken a short-term focus," CEO Steve Abramson reassured analysts in a conference call. "We believe more strongly than ever that despite this near-term slowdown a road to greater OLED adoption continues to stretch far and wide before us." With the stock now down more than 50% over the past year and trading at a forward P/E of 14, now might even be a good time to buy into those still-attractive long-term trends.