(Updates to add the latest stock move in the headline and first paragraph.)

Amkor Technology (AMKR) shares were down 25% in Tuesday trading after the company's weak Q3 revenue guidance.

Amkor reported Q2 earnings late Monday of $0.70 per diluted share, up from $0.22 a year earlier.

Analysts polled by FactSet expected $0.48.

Revenue for the three months ended June 30 was $1.90 billion, up from $1.51 billion a year earlier.

Analysts expected $1.81 billion.

For Q3, the company expects revenue of $1.95 billion to $2.05 billion. Analysts expect $2.10 billion.

Price: 45.40, Change: -15.31, Percent Change: -25.22