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.

What: Shares of unmanned aircraft systems specialist AeroVironment (Nasdaq: AVAV) fell 10% today after its quarterly results came in below Wall Street expectations.

So what: AeroVironment's first-quarter miss was so wide -- loss of $0.06 on revenue of $58.7 million versus the consensus loss of $0.03 and a top-line of $62.5 million -- that analysts have no choice but to lower their valuation estimates yet again. While the quarter was hurt by contract delays, a clear decrease in drone sales reinforces fears over the company's exposure to defense spending cutbacks.

Now what: Despite the first-quarter miss, management maintained its full-year EPS outlook of $1.41-$1.51 on revenue of $348 million-$370 million. "We are focusing bid and proposal and research and development investments on multiple adjacent market and new development initiatives where we continue to receive positive customer feedback," Chairman and CEO Tim Conver said. "At the same time, we are managing other costs in the business to achieve our financial plan for the fiscal year." With the stock flirting with its 52-week low today, it might even be an opportune time to bet on it.

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