What happened

Amkor Technology (NASDAQ:AMKR) stock jumped on Tuesday, rising as much as 20.1%. As of 3:05 p.m. EDT, the stock was up 18.9%. Shares of the semiconductor packaging and test services company rose following its third-quarter earnings release, which featured better-than-expected earnings per share (EPS).

The quarter's solid results reflected "strength in mobile communications," said Amkor CEO Steve Kelley in the company's third-quarter earnings release.

A chart of a stock price moving higher.

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So what

Amkor reported net sales of $1.144 billion, up 7% sequentially and about flat year over year. Earnings per share was $0.24, down from $0.25 in the year-ago quarter but above a consensus analyst estimate for $0.17. Management had guided for third-quarter earnings per share to be between $0.12 and $0.23.

"Better than expected gross profit and EPS were driven primarily by improved operating leverage," said Amkor CFO Megan Faust.

Now what

For Amkor's fourth quarter, management expects net sales between $1.02 billion and $1.1 billion and EPS between $0.02 and $0.14.

Importantly, Faust said the company completed a debt refinancing during the quarter that will save the company $11 million annually in interest payments.