ASP Isotopes ASPI Stock Drops 5.08% as Investor Caution Weighs Before Year-End Close

On December 31, 2025, shares of ASP Isotopes (NASDAQ:ASPI) fell 5.0788% in pre-market trading, signaling investor caution ahead of the year-end close.

The decline followed a significant insider transaction, as CFO Heather Kiessling sold 80,000 shares at $5.80 each, totaling $464,000. This marked a 9.85% reduction in her personal stake, raising concerns about potential negative signals from management.

Analyst sentiment remained divided. Cantor Fitzgerald upgraded the stock to “overweight” with a $13.00 price target, while Weiss Ratings reiterated a “sell (d-)” rating. Despite a $11.00 target from Canaccord Genuity, the stock’s average rating remains “Hold” with a $13.00 consensus price.

Recent earnings missed expectations, reporting a -$0.15 EPS against a forecast of -$0.10, alongside a negative net margin of 1,259.12%. This performance, coupled with institutional selling pressure in prior quarters, underscores ongoing challenges for the development-stage isotope producer.

Notably, several hedge funds significantly increased stakes in the third quarter, including FNY Investment Advisers and Tudor Investment Corp, suggesting a split between short-term bearish signals and longer-term strategic interest.