DYN down 17.0% on Sep 9 2026 with no filing that explains it
DYN-17.0%on Wed Sep 9 2026
Dyne Therapeutics, Inc. Common Stock was down 17.0% on the day at $20.16, ranked #12 on 7.9× its usual five-minute volume, when TapeRank recorded this unexplained move at 04:07 ET during the pre-market session.
THE DAY ON THE LIST · 1 EVENT
- 04:07 ETUNEXPLAINED MOVE · PRE-MARKET
$20.16 · ▼ 17.0% ON THE DAY · 7.9× 5M RVOL · RANK #12
UNEXPLAINEDCONFIDENCE4/5DYN is down 17% premarket on elevated volume with no news or filings that explain a move of this magnitude. The only recent filings are routine Form 4 insider transactions, which do not typically drive double-digit price swings.
WHYA 17% premarket decline against nothing but routine Form 4 insider filings is a large move with essentially no disclosed catalyst behind it.ANALYZED 04:07 ET · <1 MIN AGO · ANTHROPIC/CLAUDE-SONNET-5THE ROW AND SESSION LEVELS AT 04:07 ET
LAST20.16DAY▼ 17.0%5 MIN▼ 0.79%5M RVOL7.9×5M $VOL$207KFLOAT*186.7MRANK#12SESSIONPRE-MARKETVWAP20.30HOD20.91LOD17.00OR HIGH—OR LOW—PREV CLOSE24.28PM HIGH20.33PM LOW20.16GAP▼ 29.65%* FLOAT IS SHARES OUTSTANDING; TRUE FREE FLOAT IS NOT AVAILABLE
— MEANS THE LEVEL DID NOT EXIST YET AT THAT INSTANT, NOT ZERO
THE SESSION
- 09:30 ETOpened at $19.38, -20.2% on the previous close of $24.28
- 09:30 ETRegular-session low, $18.97
- 10:13 ETRegular-session high, $20.16
- 15:59 ETLast trade of the regular session, $19.18, -21.0% on the previous close of $24.28
- Volume: 4.8M shares in regular hours, 56K before the open
DYN opened the session at $19.38, already down about 20% from the prior close of $24.28, after TapeRank flagged the stock premarket at 04:07 ET as an unexplained 17% decline on elevated volume, with confidence 4 of 5 and no catalyst beyond routine Form 4 insider filings that do not typically move a stock this much. Shares dipped to $18.97 at the open before climbing to a session high of $20.16 at 10:13 ET, then faded through the day to close the regular session at $19.18, down roughly 21% on the day, with no halts recorded and no further news or filings to explain the move.
WRITTEN THU OCT 15 2026 17:43 ET BY ANTHROPIC/CLAUDE-SONNET-5 FROM THE FACTS ON THIS PAGE
FILINGS · 24H BEFORE THE MOVE
- TUE 12:15 ET4 — Insider transactionSEC 4
- TUE 12:14 ET4 — Insider transactionSEC 4
- TUE 12:13 ET4 — Insider transactionSEC 4
On the tape right now
WHERE THE LIST STOODWED NOV 4 2026 · 13:49 ETRECORDED LIVE · 742 QUALIFY
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