What happened

Shares of Dublin, Calif.-based human resources facilitator TriNet Group (TNET -0.01%) closed 23.1% higher on Friday after the company reported its fourth-quarter 2018 earnings results the previous evening.

TriNet earned $0.40 per share on sales of $917 million in the quarter, with "net service revenues" of $225 million. It seems this was the number Wall Street was focusing on when it estimated TriNet would report sales of $213 million -- thus, the company "beat" on sales.

TriNet further noted that when adjusted for one-time items, its profit would have been $0.59 per share -- also more than the $0.52 pro forma profit that the Street had been looking for.

Folded dollar bill pointing up

Image source: Getty Images.

So what

Total quarterly revenue running through TriNet increased 8% year over year, and the $225 million in revenue net of "insurance costs" grew 10% year over year. On the other hand, the $0.40 per share in GAAP profit TriNet earned was less than half of the $0.92 profit booked a year ago. (On the third hand, the company's claimed $0.59 pro forma profit was up 28% year over year).

For the full year, net service revenue likewise increased 10% to $893 million, GAAP profit grew 6% to $2.65 per share, and pro forma profit spiked 52% higher to $3.02.

Check out the latest TriNetearnings call transcript.

Now what

Management did not give new guidance for what to expect in 2019. For what it's worth, though, Wall Street is predicting the first quarter of 2019 will see TriNet earn $0.79 per share on net service revenue of $236 million. Full-year profits in 2019 should be $3.11 (presumably, pro forma) per share on net service revenue of $943.3 million, according to the analysts.

If they're right, that will work out to an unaggressive 6% sales growth rate, and only 3% growth in profits.