07:16 AM EDT, 05/29/2026 (MT Newswires) -- PRF Technologies ( PRFX ) shares were up over 250% in Friday premarket activity after the company updated investors on the development of its DeepSolar Predict renewable energy revenue optimization platform ahead of a planned commercial launch.

Sunlands Technology Group ( STG ) stock was 123% higher after the company said its board authorized a plan to buy back up to $50 million of its Class A ordinary shares in the form of American depositary shares over the next 36 months.

HUB Cyber Security ( HUBC ) shares were up 52% after an investor filed an amended disclosure with the US Securities and Exchange Commission, showing a 15.6% beneficial ownership stake in the company.

Nexera Technologies ( NEXR ) stock was 47% higher, adding to a 5% rise in the Thursday session.

Olenox Industries ( OLOX ) shares were up 46% after the company said it closed the acquisition of CS Digital Ventures.

QTREX Quantum ( QTEX ) stock was 36% higher following the previous session's 42% increase.