What happened

Wabash National (NYSE:WNC) makes the back end of trucking companies' ubiquitous tractor-trailers -- the trailers. It's not the sexiest business, but Wabash proved it can be a very profitable business when it reported its Q4 earnings last night.

How profitable is the business of trailer-making? Profitable enough to propel Wabash National stock up 9.5% by the close of trading Wednesday, after investors saw the results. For the fiscal fourth quarter, Wabash earned $0.80 per diluted share ($0.36 pro forma). By either measure, the company beat Wall Street estimates, which had fixed on $0.34 as Wabash's likely profit.

Tractor trailer driving into sunrise

Image source: Getty Images.

So what

Wabash's $0.80-per-share Q4 profit was more than twice the $0.36 the company had earned one year ago. The strong finish lifted the company to $1.78 in earnings per share for the year, nearly matching 2016's performance, and making 2017 Wabash's second most profitable year in the past five years -- even as 2017 was Wabash's second worst  year of the past five for revenue (down 4% from 2016).

Now what

Despite the strong net profit, operating profit margins at Wabash were rather weak last year -- just 7.4%. Nevertheless, Wabash management is forecasting that 2018 will be a good year. Sales are expected to grow as much as 19% to about $2.1 billion. Earnings should range from $1.86 to $2.02 per diluted share. Thus, even at the low end of guidance, this would represent modest 4% earnings growth -- and make 2018 the company's most profitable year in the past five.

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