Guarini Kathryn sold $320K of REGN
Guarini Kathryn sold 400 shares of REGENERON PHARMACEUTICALS, INC. (REGN) at $800.00 ($0.32M total) on 2026-08-10 under a Rule 10b5-1 trading plan.
How this was made
The 30-second read
Why it matters
The only new fact is the reported open-market sale of 400 shares at $800/share on Aug. 10, with a 10b5-1 pre-arranged plan confirmed.
Market read
Traders may note insider selling, but the 10b5-1 structure and modest transaction size suggest limited incremental impact.
What to watch
The filing does not disclose reasons for the sale, and the post-transaction holdings (603 shares) are small relative to typical institutional float, limiting signal strength.
Background
The article is an SEC Form 4 insider transaction disclosure for Regeneron Pharmaceuticals, Inc.
Ticker impact
Regeneron director Kathryn Guarini sold 400 shares in an open-market transaction at $800/share under a 10b5-1 plan, filed Aug. 12.
Low likelihood of a sustained price move; any reaction is likely muted given the stated 10b5-1 pre-arranged plan.
Form 4 reports the sale size and price ($320,000 total) and confirms a pre-arranged 10b5-1 plan, which typically reduces interpretive signal versus discretionary selling.
Market effects
Minimal. Insider transaction in a single biotech name does not materially reset sector expectations.
None indicated.
None indicated.
Counterpoint
Because the sale is under a 10b5-1 plan, it may reflect routine liquidity needs rather than bearish expectations, so any negative read-through may be overstated.
Key entities
- issuerREGN
Regeneron Pharmaceuticals, Inc., the company whose director insider sale is disclosed.
- insiderKathryn Guarini
Director of Regeneron who sold 400 shares under a 10b5-1 plan.
