What happened 

Shares of branded towing and trailer company Horizon Global Corp (HZN) plunged as much as 29.2% in trading Thursday after lowering its full-year 2017 guidance. At 12:50 p.m. EST shares were still down 27.1% on the day.

So what

Revenue is now expected to grow between 37.2% and 37.6% in full-year 2017 versus previous guidance of 38% to 41%. Operating profit guidance is now expected to be $34 million to $36 million, well lower than a previous range of $38.2 million to $44.2 million.

Truck pulling a trailer on the highway.

Image source: Getty Images.

Where guidance got really bad was on the bottom line. Diluted loss per share is expected to be $0.02 to $0.08 versus a previously expected profit per share of $0.50 to $0.60. Some of the negative impact on earnings will be one-time effects of the tax bill passed in December, but unexpected delays in moving to a new distributor and lower sales were a big impact as well.

Now what

Some of the factors impacting Horizon Global's results will be one-time events, but investors have to be concerned about the company growing more slowly than expected and margins not hitting expectations. Even on an adjusted basis earnings of $0.88 to $0.96 per share fell well below previous guidance of $1.04 to $1.14.

I think there's value given the fact that shares trade at just 10 times the midpoint of earnings per share guidance, but if this is a sign that long-term growth will be hindered or margins are going to be lower, then the upside for shares will be limited. Management will have to explain exactly where the company is headed in early March when earnings are released.