Senti Biosciences, Inc. (NASDAQ: SNTI) has 25,555,024 shares registered for resale under a shelf registration — a filing that lets holders sell shares into the open market — that went effective on September 24, 2026. Those shares, issuable upon exchange of $16 million in senior secured convertible notes, represent 82% of the company's 31.14 million shares outstanding and roughly 3.2 times the reported public float of 8.04 million shares.

None of those shares exist yet. But the company can force their creation.

The Merger Trigger

SNTI has agreed to merge with Celadon Partners SPV 35, with an outside closing date of December 31, 2026. When the merger closes, the company can compel exchange of all outstanding notes into common stock regardless of market conditions. That single event would push up to 25.56 million newly issued, freely tradeable shares into a float that today holds just 8.04 million.

The notes carry a fixed exchange price of $0.6261, but they include a full-ratchet anti-dilution clause — meaning that if the company issues any shares below that price, the exchange price resets downward to match, and the number of shares the noteholders receive increases proportionally.

Where the Ratchet Gets Pulled

A Celadon affiliate has committed to purchase $2.5 million of common stock at the Nasdaq Minimum Price — a floor set by exchange rules, currently around $0.33 — at or near the merger closing. That purchase would price well below $0.6261 and could trigger the full ratchet. If it does, the note-exchange shares balloon from 25.56 million to approximately 48.6 million, equal to roughly six times the current float and 156% of shares outstanding.

The company also has roughly $6.0 million remaining on a dormant at-market facility — a program that lets it sell shares directly into the market through a broker. Any ATM sale near the current market level would likewise price below the ratchet threshold. Under the merger agreement, the acquiring parent can direct those sales.

More Behind It

Beyond the $16 million already committed, another $24 million in notes on identical terms can still be issued under the amended purchase agreement, with lead investor consent. At $0.6261, that is 38.3 million additional shares. If the ratchet has already reset to $0.33, the figure climbs far higher.

SNTI is authorized to issue up to 500 million shares. With 31.14 million outstanding today, there is ample room in the charter.

The 31.7 million warrants outstanding at a $2.30 strike sit roughly seven times above current levels. They add little near-term supply, and under the merger agreement, holders receive a cash buyout based on a Black-Scholes valuation — a formula estimating the warrants' theoretical value — rather than shares.

Structural Scorecard

ShareStructure assigns SNTI a dilution risk score of 6 out of 10 (ELEVATED). The convertible-note overhang dominates the picture: the ratchet clause, the merger-triggered forced exchange, and the newly effective resale registration combine to create what the data shows as up to 33.8 million shares that could enter the float within 90 days and 72.1 million within 12 months. To put that in scale, 72.1 million shares is roughly nine times the current float.

A reverse stock split has been proposed at the upcoming annual meeting, partly to address a Nasdaq bid-price deficiency deadline of February 23, 2027. A prior 1-for-10 reverse split was completed in July 2024. A second split would reduce the per-share numbers proportionally but would not change the ratio of overhang to float.

The note maturity date is November 23, 2026. If the notes are not exchanged by then, the company owes 200% of principal — $32 million — in cash, against just $6.5 million of cash on hand as of the last quarterly filing.