Applied Materials Inc, the world’s largest supplier of tools used to make semiconductors, reported lower-than-expected quarterly revenue, largely due to slowing smartphone sales.

The company’s shares fell 6.2% to $28.82 in after-hours trading. The stock had gained 64.6% this year through Thursday’s close.

Applied Materials, whose results are seen as the bellwether for the chip industry, reported a 39.2% jump in fourth-quarter revenue to $3.30 billion, but narrowly missed analysts’ average estimate of $3.31 billion.

The company’s net income rose to $610 million, or 56 cents per share, in the three months ended Oct. 30 from $336 million, or 28 cents per share, a year earlier.

Excluding items, the company earned 66 cents per share, beating analysts’ average estimate of 65 cents, according to Thomson Reuters I/B/E/S.

Applied Materials has been benefiting from higher demand for 3D NAND memory chips from smartphone makers and the shift to organic light-emitting diode technology for displays.