Pacific Biosciences (NASDAQ: PACB) CFO sells 661,815 shares in trading plan

What happened

Pacific Biosciences Of California, Inc. (NASDAQ: PACB) said James R. Gibson II sold 661,815 shares on 2026-10-06. The filing identifies Gibson as Chief Financial Officer and says the trades were made under a Rule 10b5-1 trading plan adopted on May 22, 2026.

It also says Gibson exercised 500,000 stock options at $1.18 a share and sold common stock at a weighted average $3.108 a share. The sales ranged from $3.00 to $3.33 a share. After the sale, Gibson held 1,083,848 shares, all directly owned. The derivative table shows 1,500,000 stock option shares beneficially owned after the transaction. The stock option line lists 500,000 shares acquired on 10/06/2026. The reporting person filed the Form 4 on 10/08/2026.

Key numbers

Metric	Latest	Change	Source
Shares sold	661,815 shares		SEC Form 4
Pre-trade holding	1,745,663 shares		SEC Form 4
Weighted average sale price	$3.108 per share		SEC Form 4
Sale proceeds	about $2.06 million		SEC Form 4
Shares held after sale	1,083,848 shares		SEC Form 4
Stock options exercised	500,000 shares		SEC Form 4

Read more: Pacific Biosciences Of California (PACB) stock analysis and investment case

Why it matters

OptimistFi's case is that PacBio can create value if its differentiated sequencing drives repeat customer usage and margin expansion before liquidity pressure forces dilution. The sale is mixed for that view because it trims a sizable holding, but the strongest counterpoint is the Rule 10b5-1 plan.

Gibson's 661,815 shares were about 37.9% of the 1,745,663 shares held before the trade. The filing also shows a separate exercise of 500,000 stock options at $1.18 a share, then a sale of common stock at a weighted average $3.108 a share.

After the transaction, Gibson still held 1,083,848 shares. That keeps a large direct stake in place even as the sale brought in about $2.06 million in proceeds. The filing's plan date, May 22, 2026, makes the trade look scheduled rather than reactive, but it still reduces the direct share count.

For a company where liquidity pressure matters, the mix of option exercise, sale price range and remaining ownership is the part investors can check now. The derivative table also lists 1,500,000 stock option shares beneficially owned after the transaction, which leaves future vesting and exercise activity relevant to alignment.

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What's next

The remaining stock option covers 1,500,000 derivative shares, and the filing says one-fourth vested on the one-year anniversary of grant. The balance vests monthly over the next three years if Gibson continues to serve through each vesting date. More sales as shares vest would weaken the mixed read, while holding the stock through future vesting dates would keep the transaction looking pre-scheduled. The option expires on 03/31/2035.

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