ON Semiconductor's fourth-quarter revenue of $1.53 billion fell just short of analysts' expectations, despite a positive earnings surprise with 64 cents per share, surpassing forecasts. The company experienced an 11.2% year-on-year sales decline but remains focused on growth in AI, automotive, and industrial sectors. Notably, it completed significant share buybacks totaling $175.6 million and expects first-quarter revenue to be around $1.49 billion, indicating ongoing confidence in key markets despite shrinking margins.