Artificial intelligence drone software maker Swarmer shares pulled back 16.4% in premarket trading on Thursday.

Swarmer’s shares have surged 1,000% in two days, making it the best debut for a US stock in nearly a year.

The Austin, Texas-based company’s shares closed up 77% to $55.00 on Wednesday, after closing up 520% on Tuesday. It is now the best showing for a newly listed stock since Newsmax Inc.’s 2,230% two-day gain last year.

Swarmer does not manufacture drones, but its AI technology can be used to deploy and coordinate drone swarms, like a flock of birds. Its platform has been used in Ukraine with more than 100,000 real-world missions in active combat since April 2024, according to a regulatory filing.

The two-day rally comes amid a growing investor interest in the defense industry, along with the emergence of software-driven, autonomous systems and a broader move in modern warfare toward low-cost weapons.

Swarmer’s management includes co-founders Serhii Kupriienko and Alexander Fink, who serve as global chief executive officer and US chief executive officer, respectively, according to its regulatory filing. The company was incorporated by Fink in October 2023.