Constantin Ionel Stefan net worth and biography

Constantin Stefan Biography and Net Worth

Dr. Ionel Stefan is Amprius’ Chief Technology Officer. He joined Amprius in its very early days in 2009 as a Senior Scientist, initially to lead electrochemistry for silicon nanowire anode-based lithium-ion batteries. Dr. Stefan now leads Amprius' development of silicon nanowire electrochemistry, cell technology --including material design, cell design and engineering -- and product development. At Amprius, he has served as Principal Investigator on multiple projects, including NASA, Army, DOE and USABC-funded research and development efforts.

Dr. Ionel Stefan received his Ph.D in Chemistry from Case Western Reserve University(2002) with research activities focused on the development of new materials and devices for energy production and storage. He was a Postdoctoral Fellow at Lawrence Berkeley National Laboratory, developing high temperature solid oxide fuel cells. Later, at Nanosys, he became familiar with silicon nanowire materials and developed methanol fuel cells with catalysts supported on nanowire electrodes. At Nanosys, Ionel began developing silicon anodes for lithium-ionbatteries. At Amprius since 2009, he leads development of materials and electrochemistry for silicon anode-based cells and products.

What is Constantin Ionel Stefan's net worth?: The estimated net worth of Constantin Ionel Stefan is at least $10.06 million as of November 21st, 2025. Dr. Stefan owns 821,951 shares of Amprius Technologies stock worth more than $10,060,680 as of December 4th. This net worth evaluation does not reflect any other assets that Dr. Stefan may own. Additionally, Dr. Stefan receives an annual salary of $299,700.00 as CTO at Amprius Technologies. Learn More about Constantin Ionel Stefan's net worth.
How old is Constantin Ionel Stefan?: Dr. Stefan is currently 51 years old. There are 3 older executives and no younger executives at Amprius Technologies. The oldest executive at Amprius Technologies is Dr. Kang Sun Ph.D., President, CEO & Director, who is 69 years old. Learn More on Constantin Ionel Stefan's age.
What is Constantin Ionel Stefan's salary?: As the CTO of Amprius Technologies, Inc., Dr. Stefan earns $299,700.00 per year. There are 3 executives that earn more than Dr. Stefan. The highest earning executive at Amprius Technologies is Dr. Kang Sun Ph.D., President, CEO & Director, who commands a salary of $1,250,000.00 per year. Learn More on Constantin Ionel Stefan's salary.
How do I contact Constantin Ionel Stefan?: The corporate mailing address for Dr. Stefan and other Amprius Technologies executives is , , . Amprius Technologies can also be reached via phone at 800-425-8803 and via email at [email protected]. Learn More on Constantin Ionel Stefan's contact information.
Has Constantin Ionel Stefan been buying or selling shares of Amprius Technologies?: During the past quarter, Constantin Ionel Stefan has sold $252,241.92 in shares of Amprius Technologies stock. Most recently, Constantin Ionel Stefan sold 25,024 shares of the business's stock in a transaction on Friday, November 21st. The shares were sold at an average price of $10.08, for a transaction totalling $252,241.92. Following the completion of the sale, the chief technology officer now directly owns 821,951 shares of the company's stock, valued at $8,285,266.08. Learn More on Constantin Ionel Stefan's trading history.
Who are Amprius Technologies' active insiders?: Amprius Technologies' insider roster includes Jonathan Bornstein (Insider), Justin Mirro (Director), Constantin Stefan (CTO), Kang Sun (Chief Executive Officer & Board Director), and Sandra Wallach (CFO). Learn More on Amprius Technologies' active insiders.
Are insiders buying or selling shares of Amprius Technologies?: During the last year, insiders at the sold shares 13 times. They sold a total of 1,399,717 shares worth more than $12,837,479.43. The most recent insider tranaction occured on November, 21st when CTO Constantin Ionel Stefan sold 25,024 shares worth more than $252,241.92. Insiders at Amprius Technologies own 12.9% of the company. Learn More about insider trades at Amprius Technologies.
Information on this page was last updated on 11/21/2025.

Constantin Ionel Stefan Insider Trading History at Amprius Technologies

Transaction Date	Buy/Sell	Number of Shares	Average Share Price	Total Transaction	Shares Held After Transaction
11/21/2025	Sell	25,024	$10.08	$252,241.92	821,951
8/21/2025	Sell	19,159	$6.82	$130,664.38	846,975
5/21/2025	Sell	20,366	$2.43	$49,489.38	866,134
2/21/2025	Sell	9,066	$3.13	$28,376.58	421,489
11/21/2024	Sell	8,575	$1.96	$16,807.00	430,555
8/21/2024	Sell	8,800	$1.04	$9,152.00	386,168
5/21/2024	Sell	5,272	$1.33	$7,011.76	399,089
9/14/2023	Sell	46,370	$3.66	$169,714.20	63,421

Constantin Ionel Stefan Buying and Selling Activity at Amprius Technologies

Amprius Technologies Company Overview

Amprius Technologies, Inc. produces and sells ultra-high energy density lithium-ion batteries for mobility applications. The company offers silicon nanowire anode batteries. Its batteries are primarily used for existing and emerging aviation applications, including unmanned aerial systems, such as drones and high-altitude pseudo satellites. The company was incorporated in 2008 and is headquartered in Fremont, California.

Today's Range

Now: $12.24

$11.27

$12.49

50 Day Range

MA: $11.99

$10.08

$14.67

2 Week Range

Now: $12.24

$1.63

$16.03

Volume

6,704,899 shs

Average Volume

6,959,221 shs

Market Capitalization

$1.60 billion

P/E Ratio

N/A

Dividend Yield

N/A

Beta

2.94

Constantin Stefan Biography and Net Worth

What is Constantin Ionel Stefan's net worth?

How old is Constantin Ionel Stefan?

What is Constantin Ionel Stefan's salary?

How do I contact Constantin Ionel Stefan?

Has Constantin Ionel Stefan been buying or selling shares of Amprius Technologies?

Who are Amprius Technologies' active insiders?

Are insiders buying or selling shares of Amprius Technologies?