What happened 

Shares of lighting and building management solutions company Acuity Brands, Inc. (NYSE:AYI) jumped as much as 19.3% in trading Tuesday after reporting fiscal third-quarter 2018 results. Shares fell slightly as the day went on but were trading 12.4% higher at 12:30 p.m. EDT. 

So what

Revenue was up 5.9% in the quarter to $944 million and net income fell 11.2% to $73 million, or $1.80 per share. On an adjusted basis, which pulls out one-time items, earnings were $2.37 per share, up 10.2% versus a year ago.

A person holding an LED lightbulb.

Image source: Getty Images.

Analysts were only expecting $898.9 million in revenue and $2.17 per share in adjusted earnings, so this was a big earnings beat for Acuity. Management said they expect the lighting market to "improve modestly" in the second half of the year, which is a mildly bullish sentiment coming out of a solid quarter.

Now what

I wouldn't overreact too much about a single quarter of Acuity Brands because the company's performance is very volatile. It was only three months ago that shares plunged double digits on a weaker than expected quarter. As good as third-quarter results looked today, the stock is only up because results beat expectations. In the fiscal fourth quarter, revenue expectations are $970 million and earnings are expected to be $2.62 per share. If growth doesn't continue, the stock could give back gains, so investors would be wise to look at Acuity's long-term growth trends rather than focus on today's results alone.

Travis Hoium has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.