Gross profit totaled $1.18 billion, a year-over-year increase of 38.9%. Gross margin of 39.0% increased 110 basis points year-over-year, mainly due to lower unloading charges, manufacturing efficiencies and improved mix partially offset by negative currency effects, net of hedging. First quarter gross margin was 50 basis points above the mid-point of the Company’s guidance mainly due to better product mix.
Operating income increased 90.3% to $440 million, compared to $231 million in the year-ago quarter. The Company’s operating margin increased 420 basis points on a year-over-year basis to 14.6% of net revenues, compared to 10.4% in the 2020 first 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 280.4% to $85 million. Operating margin was 8.2% compared to 3.0%.
Analog, MEMS and Sensors Group (AMS):
- Revenue increased in Analog, MEMS and Imaging.
- Operating profit increased by 5.4% to $187 million. Operating margin was 17.2% compared to 20.8%.
Microcontrollers and Digital ICs Group (MDG):
- Revenue increased in Microcontrollers and decreased in RF Communications.
- Operating profit increased by 140.5% to $172 million. Operating margin was 19.4% compared to 11.5%.
Net income and diluted earnings per share increased to $364 million and $0.39, respectively, compared to $192 million and $0.21, respectively, in the year-ago quarter.
Cash Flow and Balance Sheet Highlights
| Trailing 12 Months | ||||||
| (US$ m) | Q1 2021 | Q4 2020 | Q1 2020 | Q1 2021 | Q1 2020 | TTM Change |
| Net cash from operating activities | 682 | 922 | 399 | 2,376 | 1,927 | 23.3% |
| Free cash flow (non-U.S. GAAP) | 261 | 512 | 113 | 776 | 677 | 14.6% |
