TWST Shorts Hit a Year Low as Stock Leads the Peer Group

Twist Bioscience is the standout mover in synthetic biology this week, with its shares up 12% while most of its closest peers barely moved, and short interest has pulled back to its lowest level in over a year.

Among correlated names, GRAL added 20.8% on the week and ABSI gained 16.5%, so the AI-genomics trade broadly caught a bid. But Twist's 12% weekly gain compares to a peer median of roughly 2.6%, and unlike NTRA or CDNA, which each moved around 1% to 2%, Twist's run came alongside a meaningful shift in positioning rather than in spite of one. Short interest has dropped to 16.1% of the free float, down from around 21% to 26% for most of October and a peak near 25.8% at the start of the month. That's the lightest short position Twist has carried in at least a year, and the 20% decline in short interest over the past month is the sharpest compression in the data.

The borrow market reinforces that picture. Availability is loose at 518%, meaning there are roughly five shares available to lend for every one already borrowed. Borrowing costs sit at just 0.44%, barely changed from a month ago and well within normal territory. This is not a short-squeeze setup: shorts have been reducing exposure on their own terms, not being forced out. Options positioning tells the same story from a different angle. The put/call ratio has fallen to 0.57, more than two standard deviations below its 20-day average of 0.72. That is the most call-heavy options setup Twist has seen relative to recent history, suggesting fresh positioning leaning toward further upside rather than hedging against it.

The Street has moved decisively in the same direction. TD Cowen raised its target to $190 from $115, Barclays lifted to $215 from $112, and Guggenheim went to $212 from $107, all within the past month. Those are not incremental revisions but full re-ratings, driven by what analysts describe as AI-driven order momentum they now expect to reach triple-digit percentage growth in fiscal 2026, with AI-related revenue of at least $50 million versus roughly $25 million in fiscal 2025. Jefferies initiated at Hold with a $150 target, and BWS Financial maintains a Sell at $45, giving the bearish camp a floor argument centred on pricing pressure from Danaher, Agilent, and Roche, and the risk that AI demand proves narrower than the August rally implied. The consensus mean target is $168, a modest premium to the current price of $159.85, though several of the most recent upgrades sit well above that level. Factor scores are mixed: EPS surprise ranks in the 90th percentile, and the 12-month forward EPS growth estimate scores in the 80th percentile, but 30-day and 90-day EPS momentum both rank in the bottom 2%, meaning near-term estimate revisions have been negative even as the longer-term story improved.

Institutional activity has been aggressive. FMR raised its stake to 13.97% of shares as of September 30, adding over 4 million shares in the quarter. T. Rowe Price added more than 4.1 million shares in the same period, lifting its position to 6.75% of shares. Invesco added around 822,000 shares. Insider activity runs the other way: the CFO sold roughly $385,000 of stock on October 9, and the President and COO sold around $302,000 on October 23. CEO Emily Leproust sold shares totalling roughly $880,000 on October 5, all under a pre-arranged 10b5-1 trading plan, which reduces the signalling value of those transactions. The net insider position over the past 90 days is heavily negative at around $86.6 million in sales, though the plan-driven nature of most CEO selling limits what can be read into it.

One mechanical factor to watch before month-end: ORTEX puts the probability of Twist graduating from the Russell 2000 to the Russell 1000 at the December 2026 Semi-Annual Review at 55%. The rank date is October 30, with an announcement expected November 13 and an effective date of December 14. At the current price of $159.85, Twist is 1.7% above the Russell 2000 exit line of $162.62, meaning the stock needs to hold above that level to stay on course for deletion from the smaller index. The potential Russell 1000 addition would require an estimated $529 million in tracker buying spread over 1.4 days of normal volume. The deletion from the Russell 2000 carries an estimated $1.4 billion in tracker selling over 3.9 days of volume. In 351 comparable Russell 2000 deletions, the median move from announcement to effective date was negative 4.3%, and 80% of those names moved in that direction. The next earnings print is November 12, the day before the index announcement, which puts two of the most significant near-term catalysts within 24 hours of each other.

The price level that decides the index outcome, $162.62, is the number worth watching through October 30.