Next-Gen Battery Stock Amprius Plummets 7% in a Day, $200 Million Vanished

Amprius Technologies Inc. (NASDAQ: AMPX) closed at $15.57 on May 16, down 7.43%.
In a single day, its market capitalization fell by approximately $150 million (around ₩200 billion) to about $2.2 billion (around ₩3 trillion), and trading volume topped 4 million shares.

In its Q1 2026 earnings report released May 6, the company posted revenue of $28.53 million (roughly ₩40 billion), a 153% year-over-year increase, and raised its full-year 2026 revenue guidance to at least $130 million (approximately ₩180 billion).

Also in May, Amprius announced a strategic partnership with Martnet to supply its high-energy silicon-anode batteries for an autonomous drone delivery platform, boosting expectations for growing demand in the drone and aviation markets.

Headquartered in Fremont, California, Amprius Technologies develops silicon-anode lithium-ion batteries that offer about twice the energy density of conventional graphite cells, targeting aerospace, defense and mobility applications.

Known for an asset-light model that leverages contract manufacturing and partnerships in markets such as Korea instead of building its own plants, the company relies heavily on aviation and defense customers—including drones and unmanned aerial vehicles—for a significant portion of its sales.