Editor’s notes

Tuesday brought a 100% gap in an identity-security microcap, a take-private with a contingent payment, and a $2 billion strategic investment in a large-cap biotech. Most of the list faded: 9 of the top 10 closed below their opening price, though all 10 finished above the prior close.

Market context: The S&P 500 slipped as consumer confidence fell to a 12-year low (TheStreet session recap).

By the numbers: Under FennEdge's default filters, 9 stocks opened at least 20% above their prior close.

The list is ranked by opening gap, not market cap; Summit Therapeutics, for example, is not a small-cap company.

Notable tickers

BKYI — BIO-key International

• Catalyst: On Sep 29, BIO-key announced a partnership with Dubai-based Al Majlis Group to market its identity-security platform in the UAE and Saudi Arabia (Stock Titan copy of the release). Six days earlier, it said its Passkey:YOU authenticator had received FIDO Alliance full certification (GlobeNewswire, Sep 23).
• SEC filings: An 8-K filed Oct 2 (Items 1.01, 3.02) reported four exchange agreements with Streeterville Capital, signed Sep 29. In them, $416,315.80 of note principal was exchanged for 247,805 common shares, and the original note was reported paid in full.
• Price action: Gap from $1.68 to $3.37. The extended-session high of $4.66 printed at 10:04 ET. The stock closed at $3.12, below the open but +85.7% on the day.
• Shares: 1,436,344 outstanding as of Aug 11, 2026, reflecting a 1-for-10 reverse split effective Apr 30, 2026 (10-Q). Day volume of 169.6 million was over 100 times that count.
• Links: BKYI stock page

SSTI — SoundThinking

• Catalyst: SoundThinking agreed to be acquired by affiliates of Transom Capital Group through a tender offer of $8.00 per share in cash plus one non-transferable CVR worth up to $3.00, payable if specified milestones are met (8-K, Sep 29; press release, Exhibit 99.1).
• SEC filings: The 8-K (Items 1.01, 5.02, 7.01), a Schedule TO-C on Sep 29, SC 14D9-C communications on Sep 29–30, and Schedule 13D filings on Sep 30 and Oct 2.
• Price action: It opened at $8.30, just above the $8.00 cash amount, and closed at $8.21. The extended-session high of $8.50 printed in premarket at 07:35 ET.
• Shares: 13,163,790 outstanding as of Aug 5, 2026 (10-Q).
• Links: SSTI stock page

SMMT — Summit Therapeutics

• Catalyst: Summit agreed to sell newly designated Class A convertible preferred stock to a subsidiary of AstraZeneca for $2.0 billion in gross proceeds, priced off $18.3561 per common share (8-K, Sep 29, Items 1.01, 3.02, 5.03, 8.01). Each preferred share converts into 1,000 common shares.
• Price action: The extended-session high of $19.81 printed at 04:02 ET. The stock opened at $18.91, just above the reference price, and closed at $16.39, below it.
• Shares: 797,749,602 outstanding as of Jul 17, 2026 (10-Q).
• Links: SMMT stock page

SLXN — Silexion Therapeutics

• Catalyst: On Sep 28, Silexion issued a press release on preclinical findings for SIL204 (8-K, Item 7.01).
• SEC filings: A Sep 29 8-K disclosed a warrant inducement:
  • Holders of 3,216,928 series E warrants agreed to exercise at $0.2603, cut from $0.65, for about $0.84 million in gross proceeds.
  • In return, the company issued new Series F and G warrants covering 6,433,856 shares at the same price.
  • A 424B3 followed on Sep 29, and an 8-K under Item 3.01 (listing-standard notice) had been filed on Sep 25.
• Price action: The extended-session high of $0.5099 printed in premarket at 07:18 ET. The stock opened at $0.3187 and closed at $0.3184.
• Shares: 5,560,256 outstanding as of Aug 13, 2026 (10-Q). Day volume was 256.6 million.
• Links: SLXN stock page

Terms used in these notes

• High-of-day times are the first 1-minute bar at the 04:00–20:00 ET high.
• Close vs open:
  • Held = close ≥ open.
  • Partial fade = previous close ≤ close < open.
  • Gave back gap = close < previous close.
• Shares outstanding come from SEC cover pages on the date stated and may have changed since.