TPST on September 16, 2026: why it ran

The day, step by step

• Small cap
• Momentum
• Main move: the afternoon
• Catalyst: news (day 2)
• Ask-wall break
• Stacked walls
• Float traded 3x
• Lower high after the top

The day before

On September 15, TPST ran from $0.78 to $1.71. It closed at $0.76, below where it opened. 12.35 million shares traded.

The news came after the close. At 4:05 p.m. GlobeNewsWire ran: “Tempest Secures Exclusive Option to License Clinical-Stage CD7-Targeted Lentiviral In Vivo CAR-T Platform”. The last bar we have for the 15th is $1.26.

Pre-market: the float traded by 8:01 a.m.

The first trades on the 16th were at $1.15, already above the $0.76 close. The float is 8.33 million shares.

At 5:04 a.m. Benzinga ran: “Why Tempest Therapeutics Shares Are Trading Higher By Around 50%; Here Are 20 Stocks Moving Premarket”. The price was already near $1.12 and stayed there. It sat around $1.10 until 6:33 a.m.

Then it woke up. The 6:34 and 6:35 minutes traded 354,260 and 597,883 shares. The pre-market high was $1.34 at 6:35 a.m., and that same minute dropped to $1.15. It ran to $1.27 at 6:41, then fell to $1.05 at 6:51 a.m., down 17% from $1.27. It slid to $1.01 by 7:40.

By 8:01 a.m., more shares had traded than exist in the whole float. 9.69 million shares traded before the bell.

The open and the wall at $1.20

It opened at $1.08, up 43% from the previous close. At 9:30:00 one print of 145,520 shares went through at $1.08. The first minute dipped to $1.03.

From 6:46 a.m. on, a large offer sat at exactly $1.20. At 10:00 the pile reached a peak of 215,377 shares, 2.6% of the float, across all exchanges. The stock tested the level: the 9:47 and 9:48 candles both topped out at $1.20.

Here's what happened. Starting at 10:06:00, 112,143 shares traded at exactly $1.20 in 28.3 seconds, and the wall was gone at 10:06:30. The candle pushed to $1.22. It closed at $1.17. At 10:06:44 a 43,437-share sell order swept from $1.17 down to $1.15.

Late morning: the bid wall at $1.02

After that it drifted lower, from $1.22 at 10:06 toward $1.02. From 11:18 a bid wall sat at $1.02. It peaked at 134,101 shares at 11:22, 1.6% of the float.

7,652 shares traded at $1.02 at 11:44:03, and at 11:44:04 the wall was pulled. It slid to $1.01 at 11:46. Then at 11:47 it fell to $0.97, down 21% from the $1.22 high at 10:06, on 288,043 shares in the one minute. That's the biggest minute since 10:06. By 11:51 it was back at $1.03.

The afternoon: walls stacked above

It chopped between $1.00 and $1.08 through the middle of the day. From $1.01 at 1:35 p.m. it crept up to $1.08 by 2:10. At 2:11 the volume picked up, with 103,936 shares and a 29,000-share print at $1.08 at the bid.

Above it, ask walls had piled up. One at $1.30 had been there since 7:01 a.m. One at $1.25 since 9:34. A second one at $1.20 since 10:36, and one at $1.24 since 11:43.

Here's what happened. At 2:14:15 a buy order for 84,724 shares swept from $1.17 to $1.20. Then the walls went one by one:

$1.20: 82,556 shares traded there between 2:14:40 and 2:15:04 (24.1 seconds). $1.24: 90,237 shares traded in 12.5 seconds, gone at 2:15:45. $1.25: 74,534 shares traded in 1.4 seconds, gone at 2:15:47. $1.30: 49,762 shares traded in 1.0 second, gone at 2:16:30. That's four walls in under two minutes.

The 2:18 candle reached $1.44, and a 48,327-share sell swept from $1.44 to $1.38 at 2:18:28. In the 2:19 minute, the heaviest of the day at 841,668 shares, it hit $1.48, the high of the day, up 96% from the previous close. That candle closed at $1.29, and the 2:20 candle dipped to $1.20.

The rest of the day

It came back once more. At 2:38 p.m. it pushed to $1.41, a lower high under the $1.48 top. Then it faded. It fell to $1.08 at 2:56 p.m., with sell sweeps of 53,814 shares at 2:45 and 57,476 shares at 2:51.

It climbed back to $1.32 by 3:50 p.m., lower again than $1.41. The 3:55 candle dropped to $1.20 on 222,526 shares. The last regular-session bar, 3:59, closed at $1.21.

The regular session traded 18.39 million shares. Add the 9.69 million from pre-market and 28.07 million had traded by the close: the float changed hands about 3 times. Relative volume for the day was about 43.

After hours

At 4:37 p.m. the company filed an 8-K (a current report). At 4:38 p.m. it filed a DEFA14A (proxy material).

The 4:40 minute swung from $1.05 to $1.25 on 146,723 shares, and closed at $1.12, where it opened. The ranges stayed wide: $1.32 at 4:43 p.m., $1.03 at 4:44, and a print at $0.96 at 4:48 p.m., 27% under $1.32. That minute closed at $1.11. After hours added 1.98 million shares, for 30.06 million on the whole day.

What to take from it

• One wall breaking doesn't tell you the next move. The $1.20 wall was eaten at 10:06, and a sell sweep hit $1.15 within a minute. The afternoon wall break was different: four walls went in under two minutes, and the stock reached $1.48.
• The fill cost depended on how deep the book was. The $16 at 10:06 came when only 3,427 shares were offered. At $1.25 and $1.47 the 5,000-share orders cost nothing extra.
• After the top, the next push stopped lower. $1.48 at 2:19 p.m., $1.41 at 2:38 p.m., then $1.32 at 3:50 p.m.

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