Gross profit totaled $1.61 billion, representing a year-over-year increase of 28.3%. Gross margin of 45.2% increased 640 basis points year-over-year, 20 basis points above the high-end of the Company’s guidance, principally driven by improved product mix, favorable pricing, and manufacturing efficiencies.

Operating income increased 34.8% to $885 million, compared to $657 million in the year-ago quarter. The Company’s operating margin increased 460 basis points on a year-over-year basis to 24.9% of net revenues, compared to 20.3% in the 2020 fourth quarter.

By product group, compared with the year-ago quarter:

Automotive and Discrete Group (ADG):

• Revenue increased in both Automotive and in Power Discrete.
• Operating profit increased by 129.5% to $216 million. Operating margin was 17.6% compared to 9.9%.

Analog, MEMS and Sensors Group (AMS):

• Revenue increased in both Analog and MEMS and decreased in Imaging.
• Operating profit decreased by 16.6% to $335 million. Operating margin was 26.6% compared to 28.3%.

Microcontrollers and Digital ICs Group (MDG):

• Revenue increased in both Microcontrollers and in RF Communications.
• Operating profit increased by 82.9% to $318 million. Operating margin was 29.9% compared to 20.3%.

Net income and diluted earnings per share increased to $750 million and $0.82, respectively, compared to $582 million and $0.63, respectively, in the year-ago quarter.

Cash Flow and Balance Sheet Highlights 

				Trailing 12 Months
(US$ m)	Q4 2021	Q3 2021	Q4 2020	Q4 2021	Q4 2020	TTM Change
Net cash from operating activities	881	895	922	3,060	2,093	46.2%
Free cash flow (non-U.S. GAAP)	314	420	512	1,120	627	78.6%

Capital expenditure payments, net of proceeds from sales, were $548 million in the fourth quarter and $1.83 billion for the full year 2021. In the year-ago quarter, capital expenditures, net, were $381 million.