Oklo Stock Is Down 5% Pre-Market Today – Here’s An Important Update

Oklo Inc. (OKLO), a developer of advanced nuclear systems, announced on Thursday that it has completed large-scale coolant flow testing on a prototype fuel assembly. 

The work was carried out in collaboration with the U.S. Department of Energy’s Argonne National Laboratory, as part of a government initiative supporting innovation in nuclear energy.

The testing was enabled by a voucher from the DOE’s Gateway for Accelerated Innovation in Nuclear (GAIN) program. The collected data will help confirm digital models, support manufacturability, and bring Oklo’s fuel assembly design closer to commercial readiness. 

Oklo stock traded 5% lower in the premarket on Thursday and was the top trending equity ticker on Stocktwits. Retail sentiment around the stock shifted to ‘neutral’ from ‘bullish’ territory the previous day amid ‘extremely high’ message volume levels. 

Oklo partnered with Argonne’s thermal-hydraulics division to examine how liquid coolant moves through its full-sized fuel assembly under various operating environments. Key metrics, including pressure losses and flow behavior, were captured during the testing. 

“These full-scale, prototypical tests are vital in moving us from design into production,” said co-founder and CEO of Oklo, Jacob DeWitte. “The work we’re doing through GAIN at Argonne delivers real-world data that will ultimately inform the manufacturing parameters of our fuel-assembly design.”

This testing plays a crucial role in refining Oklo’s Aurora reactor technology, a compact, next-generation fission system designed for consistent power delivery with reduced fuel waste. 

Oklo stock has gained over 517% in 2025 and over 1,493% in the last 12 months. 

Also See: Cipher Stock Soars 10% Pre-Market Today Following $3 Billion Deal With Fluidstack

For updates and corrections, email newsroom[at]stocktwits[dot]com.