Shares of Micron (MU) - Get Report were falling after the memory chip maker posted disappointing earnings guidance, but also beat expectations on revenue and earnings for its fiscal fourth quarter. 

The stock was falling 4.5% to $46.40 a share in postmarket trading, after having fallen 1.76% in regular hours. 

Adjusted earnings per share for the fiscal fourth quarter came in at 56 cents, beating Wall Street estimates of 51 cents. Revenue was $4.87 billion, beating analysts estimates of $4.588 billion.

But for its fiscal first quarter, Micron forecast adjusted EPS of 46 cents, plus or minus 7 cents, below analyst estimates of 53 cents per share. Revenue guidance came in at $5 billion, plus or minus $200 million, ahead of analyst estimates of $4.8 billion.

"Micron delivered fourth quarter results ahead of expectations, capping a fiscal 2019 in which we executed well in a challenging environment, significantly improved our competitive position, and returned cash to shareholders through share repurchases," said Micron CEO Sanjay Mehrotra. "We are encouraged by signs of improving industry demand, but are mindful of continued near-term macroeconomic and trade uncertainties. As markets recover, Micron is well positioned to address the robust secular demand for memory and storage solutions."

The stock is up 48% year-to-date. 

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