Hindsight Markets / Small-cap stocks on September 28, 2026

ACET on September 28, 2026: why it ran

Published October 9, 2026 · By Hindsight Markets

On September 28, 2026, ACET opened down 12.4% from the previous close of 9.09 and reached 10.82 at 6:48 a.m. ET. The exchange halted it once.

Previous close

9.09

Open, 9:30 a.m.

7.96

Gap at the open

down 12.4%

Pre-market high

10.82 at 6:48 a.m.

High, 4 a.m. to 4 p.m.

10.82 at 6:48 a.m.

Low, 4 a.m. to 4 p.m.

6.25

After-hours high, 4 p.m. to 8 p.m.

6.48 at 4:01 p.m.

Last trade before 4:00 p.m.

6.26

Volume

1.16 million

Relative volume

12.6x

Float

9.03 million shares, from filings as of September 28, 2026

Shares outstanding

9.36 million

Halts

1

Why it ran

News and SEC filings for ACET published between the previous session's close and the open, newest first, from the same feeds the replay shows.

1. 8:15 a.m. ET · 8-K filed with the SEC

   8-K

2. 6:45 a.m. ET · Business Wire

   Adicet Bio Announces Positive Safety and Efficacy Data from Prula-cel (formerly ADI-001) Study in Patients with Systemic Lupus Erythematosus with or without Lupus Nephritis

News via Stock News API

How it traded

The shape is a fixed rule, not a judgement: gapped 10% or more at the open, ran 10% or more from the open to the high, and faded if it gave back 30% or more of that move by the close.

The day in numbers

• Volume, from the one-minute bars: 244,637 shares before the 9:30 a.m. open (21%), 187,284 in the first 30 minutes (16%), and 728,011 in the rest of the day to 8 p.m. (63%).
• The halt at 9:30 a.m.: down 10.4% in the 5 minutes into it, reopened at 7.38, up 3.1% from the last trade before it, then down 5.1% over the next 5 minutes.

Halts

On this date the LULD plan ran under Amendment 18, in force from February 24, 2020: no band doubling at the open, and the closing doubling only for Tier 1 stocks and Tier 2 stocks whose previous close was at or below three dollars. See LULD halts or work out a band with the LULD calculator.