SION Sionna Therapeutics, Inc. Insider Trading

Director Peter A. Thompson sold 85.9K SION shares at $44.86; stock up 33.4% in 30 days yet 7.2% below 52-week high of $48.44

Director Peter A. Thompson sold 85,918 shares (85.9K shares) of Sionna Therapeutics at $44.86 on 2026-07-07 under a pre-arranged 10b5-1 trading plan, reducing his holdings by 3.4% to 2,469,959 shares (2.47M shares). The transaction occurs in a context where the stock has risen 33.4% over the prior 30 days yet remains 7.2% below its 52-week high of $48.44, and where the company reported a full-year net income of $-26,779,000.00 ($-26.8M), indicating an unprofitable fiscal year. His prior five trades at this ticker—all sells executed between 2026-04-17 and 2026-05-11—show 30-day post-transaction returns ranging from -10.0% to -26.4%, with no 90-day outcomes yet measurable for those recent trades. This sale is part of a scheduled trading plan, not a discretionary market decision.

Orbimed Advisors LLC (Director) sold 85,918 shares of SION at $44.86 on 2026-07-07 under 10b5-1 plan; sixth SION transaction in three months.

Orbimed Advisors LLC sold 85,918 shares for $3,854,281.48 on 2026-07-07 as part of a pre-arranged 10b5-1 trading plan, reducing holdings from 2,555,877 shares to 2,469,959 shares. This sale is the most recent in a sequence: the insider has executed five prior sales at SION since 2026-04-18, with measured 30-day returns of -11.9%, -20.7%, -20.7%, -26.4%, and trailing the most recent sale on 2026-06-30 where outcome is not yet measurable. The broader cross-ticker track record shows 15 prior sells with an average 30-day return of -14.3%, while the company reports a net loss of $26,779,000.00 and a market cap of $2,029,055,830.20. The current stock price of $44.94 is -7.2% from the 52-week high of $48.44, despite the stock being up +33.4% over the past 30 days and +18.6% over 90 days. The scheduled nature of this transaction under the 10b5-1 plan removes discretion from the timing, but the frequency and magnitude of sales within a three-month window against a loss-making company warrant investor scrutiny of the company's operational and financial trajectory.

Director Peter A. Thompson sold 115,844 shares of SION at $45.50 for $5.3M on 2026-06-30 via pre-arranged 10b5-1 plan; stock now $43.99

Peter A. Thompson executed a scheduled sale of 115.8K shares under a 10b5-1 trading plan, reducing his stake from 2.67M to 2.56M shares (a -4.3% reduction in holdings). The sale occurred at $45.50, above the current price of $43.99 but within the 52-week range of $14.67–$48.44. Thompson's prior same-ticker sales at SION show a pattern of negative returns: his five preceding sells at this ticker posted 30-day returns of -26.4%, -20.7%, -20.7%, -11.9%, and -10.0%. The company remains unprofitable with a net income of -$26.8M over its most recent full fiscal year, which provides fundamental context for viewing insider equity reduction. Because this sale is part of a pre-arranged 10b5-1 plan, it is scheduled rather than discretionary, limiting inference about timing intent; however, the confluence of persistent post-sale equity declines at SION, negative company earnings, and a reduction in director holdings merits attention to forward guidance and financial trajectory.

Orbimed Advisors LLC (Director) sold 115,844 shares of SION at $45.50 on 2026-06-30 under 10b5-1 plan; stock now at $43.99

Orbimed Advisors LLC executed a scheduled sale of 115,844 shares at $45.50 as part of a pre-arranged 10b5-1 trading plan. Post-transaction holdings remain substantial at 2,555,877 shares. The transaction occurred on 2026-06-30; current price of $43.99 is -9.2% from the 52-week high of $48.44. Notably, this director has recently executed four other sales at SION on 2026-05-11, 2026-05-08, 2026-05-07, and 2026-04-18—each resulting in 30-day post-sale declines of -26.4%, -20.7%, -20.7%, and -11.9% respectively. The underlying company is unprofitable, reporting net income of $-26,779,000.00 for its most recent full fiscal year. Given the scheduled nature of this sale under a 10b5-1 plan and the recent pattern of post-sale declines in the same ticker, investors should monitor whether this reflects pre-planned capital allocation or a directional shift in the insider's assessment.

Director Thompson sells ~293K shares over three days for $13.4M as stock rallies off lows but trails 52-week high.

Director Thompson Peter A. has sold nearly 293,000 shares totaling $13.4 million across three days in early May, representing his third consecutive wave of open-market sales in the trailing 36-month window. The timing is notable: the stock has rallied roughly 20% over the past three months and currently trades just below its 52-week high, yet the company remains unprofitable with ongoing quarterly losses. His prior sales at this ticker show mixed results—roughly half were well-timed exits that preceded stock declines, while the other half saw the stock rise afterward, suggesting inconsistent predictive value. The scale of this sale is material relative to his prior activity, though the unprofitable company's fundamentals and the stock's proximity to recent highs could suggest he is trimming holdings rather than expressing concern about near-term direction.

Director Orbimed Advisors Llc sells ~293k shares (~$13.4M) over three days as stock trades near its 52-week high.

Orbimed Advisors, a director at Sionna Therapeutics, disposed of roughly 293,000 shares across three trading days in early May, representing approximately 10% of their total holding and netting over $13 million. The timing is notable: the stock has rallied significantly over the prior quarter and trades near its 52-week high, a position where insiders often choose to lighten exposure. However, this director's own historical record at this company shows mixed timing on prior sales—about half of their previous exits saw the stock rise afterward (poorly timed exits), while the other half preceded stock declines (well-timed exits). The company itself remains unprofitable with substantial net losses and negative earnings, so this sale comes against the backdrop of fundamental weakness. Orbimed's filing history shows a clear pattern: 144 prior open-market sales across all holdings over the 36-month window, with this transaction representing the 145th-147th sale. The volume and frequency of sales relative to zero open-market purchases in the same period suggests this is a holder managing a large position, not an insider with accumulated operational conviction in the company.

ORBIMED ADVISORS LLC sells 55,345 shares of SION for $2,472,342.92 via scheduled 10b5-1 plan

ORBIMED ADVISORS LLC sold 2 separate tranches totaling 55,345 shares at a blended average price of $44.67 on April 17–18, 2026, for a combined $2,472,342.92. This sale reduced the director's holdings from 3,020,119 shares to 2,964,774 shares, a net decrease of 1.8%. The transaction was executed under a pre-arranged 10b5-1 trading plan, indicating the sales were scheduled rather than discretionary. Since the trades are programmatic, no timing-based inference about insider conviction is warranted; the filing reflects a pre-determined execution schedule rather than a spontaneous response to market conditions.

Director Thompson Peter A. sells 55,345 shares at $44.67 blended average under 10b5-1 plan; retains 2,964,774 shares

Thompson Peter A. executed 2 separate sales totaling 55,345 shares for $2,472,342.92 under a pre-arranged 10b5-1 trading plan, reducing his holdings by 1.8% from 3,020,119 shares to 2,964,774 shares. The sales occurred on consecutive trading days (2026-04-17 and 2026-04-18) at prices of $44.68 and $44.52, with a blended average price of $44.67. Because this transaction is scheduled under a 10b5-1 plan rather than discretionary, it reflects a pre-committed execution rather than a real-time market decision. The director maintains substantial post-transaction holdings of 2,964,774 shares, indicating continued material ownership in the company.

Director Thompson Peter A. sold 510,583 shares for $22,945,043.50 via scheduled 10b5-1 plan (Apr 14-16)

Thompson Peter A., a Director of Sionna Therapeutics, Inc., executed 3 separate sales totaling 510,583 shares (510.6K shares) for $22,945,043.50 ($22.9M) at prices ranging from $44.51 to $45.34, with a blended average of $44.94. This sale represents a reduction of 14.5% in his post-transaction holdings of 3,020,119 shares (3.02M shares). The FLAG indicates this is a pre-arranged 10b5-1 trading plan, meaning the sales were scheduled and not discretionary. As a scheduled disposition, this transaction does not reflect timing judgment or provide signal of insider conviction regarding near-term stock performance.

OrbiMed Advisors LLC sold 510,583 shares at $44.51–$45.34 (avg $44.94) for $22,945,043.50 via scheduled 10b5-1 plan

OrbiMed Advisors LLC, a director of Sionna Therapeutics, executed 3 separate sales totaling 510,583 shares for $22,945,043.50 on 2026-04-14 through 2026-04-16, reducing holdings from 3,530,702 shares to 3,020,119 shares. This disposition represents a 14.5% reduction in the director's position and was conducted pursuant to a pre-arranged 10b5-1 trading plan, meaning the sales were scheduled in advance rather than discretionary. With OrbiMed maintaining 3.02M shares post-transaction, the director retains a substantial stake in the company, though the magnitude of this scheduled liquidation ($22.9M across three days) warrants attention to any related disclosures about the plan's terms, duration, or OrbiMed's broader investment thesis.