Friday was another quiet day on Wall Street, but the overall direction of the market remained positive. Modest gains for major benchmarks sent the Dow Jones Industrials to record heights yet again, even as some market participants begin to look ahead with fear about the traditionally difficult months of September and October. Favorable numbers on the employment front bolstered investor confidence, and a lack of bad news on the geopolitical stage played a positive role as well. Yet some individual stocks suffered big losses, and Applied Optoelectronics (NASDAQ:AAOI), Trivago (NASDAQ:TRVG), and First Majestic Silver (NYSE:AG) were among the worst performers on the day. Below, we'll look more closely at these stocks to tell you why they did so poorly.

The lights go out on Applied Optoelectronics

Applied Optoelectronics stock lost a third of its value in the wake of the release of the company's fiscal second-quarter financial report. The maker of fiber-optic networking products said that revenue doubled from year-ago levels, and earnings soared by almost 800% on strong current conditions in the industry. Yet shareholders weren't satisfied with Applied Optoelectronics' guidance, which included calls for decelerating revenue growth for the current quarter. With the stock having soared over the past year, expectations among investors were extremely high, but Applied Optoelectronics' fundamentals still look strong even if the share price perhaps got ahead of itself.

Long-reach transceiver device from Applied Optoelectronics.

Image source: Applied Optoelectronics.

Trivago loses ground, money

Shares of Trivago fell nearly 19% after the company's second-quarter financial results didn't live up to investor expectations. Sales soared by two-thirds from year-ago levels, but the company wasn't able to break even on the bottom line, suffering a modest loss of 3.4 million euros. Trivago is also facing the inevitable slowdown that all high-growth companies eventually face, with those following the stock now expecting growth rates to decelerate from past levels as Trivago grows larger. Summer is the high season for travel, so Trivago's results next quarter will be telling as to whether the company's overall core strategy toward its business is poised to succeed in the long run.

First Majestic loses its crown

Finally, First Majestic Silver stock finished down 19%. The silver miner took a hit on many key fundamental metrics in its second-quarter financial report, including a 16% drop in silver production to 2.3 million ounces and a nearly one-fifth rise in all-in sustaining costs. Revenue and average realized silver price both declined, and mine operating earnings plunged by more than 85% from the year-earlier quarter. CEO Keith Neumeyer said that a number of labor issues that hurt First Majestic's results have now been resolved, but he said that investments the company is making will take 12 to 24 months to produce the positive impacts that impatient shareholders want to see. Investors will have to wait to see whether resolutions to the problems result in a rebound next quarter.

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