Hindsight Markets Small-cap stocks on September 15, 2026
TPST on September 15, 2026: why it ran
On September 15, 2026, TPST opened up 1.9% from the previous close of 0.7843 and reached 0.8110 at 6:26 a.m. ET. The exchange did not halt it.
- Previous close
- 0.7843
- Open, 9:30 a.m.
- 0.7990
- Gap at the open
- up 1.9%
- Pre-market high
- 0.8110 at 6:26 a.m.
- High, 4 a.m. to 4 p.m.
- 0.8110 at 6:26 a.m.
- Low, 4 a.m. to 4 p.m.
- 0.7430
- After-hours high, 4 p.m. to 8 p.m.
- 1.71 at 4:23 p.m.
- Last trade before 4:00 p.m.
- 0.7432
- Volume
- 12.35 million
- Relative volume
- 132.4x
- Float
- 8.33 million shares, from filings as of September 15, 2026
- Shares outstanding
- 16.54 million
- Halts
- none in the halt feed
Replay TPST's day
It starts at 3:51 p.m. ET with the real Level 2, time and sales and chart, from the same feed the replay plays, stops at 3:54 p.m. and asks what you would do. Or press Play on any moment in How it traded.
The day, step by step
- Small cap
- Momentum
- Main move: after hours
- Catalyst: licensing option
- Thin regular session
- 8-K filing
- After-hours run
The day before
On September 14, TPST traded between $0.75 and $0.83. The official previous close was $0.7843. It was a low-volume stock: 71,061 shares traded that day.
Pre-market: very thin
The first trade came at 4:03 a.m. at $0.78. Most minutes after that had no trades at all, and many that did traded a single share.
The pre-market high was $0.811 at 6:26 a.m. Only 5,512 shares traded before the bell. That is a tiny number, even for a float of 8.33 million shares.
The regular session: a slow drift down
It opened at $0.799, then slipped to $0.77 within a few minutes. By 10:02 it was trading near $0.77, and by 10:35 it was at $0.75.
The low of the morning came at 11:16, at $0.7437. After that it turned up. It climbed through $0.78 at 11:44 and $0.79 at 11:49, and at 12:00 it printed $0.8082. That was just below the pre-market high, on 66 shares.
It could not hold. By 12:29 it was at $0.7664. Through mid-afternoon it traded between about $0.75 and $0.78.
Stop It's 3:52. The price is $0.7450. TPST opened near $0.80 this morning, bounced to $0.8082 at noon, and has drifted lower since on very thin volume, with long stretches where nothing trades. The morning low was $0.7437, and since mid-afternoon the stock has mostly sat between $0.75 and $0.76. The last trade at 3:50 was $0.75, and the stock is now a hair under that, near the morning low. Would you buy here?
Press play: the real Level 2, time and sales and chart stop at 3:52 p.m. ET for your call, then show what happened. The clip starts at 3:49 p.m. ET.
The low after the open came at 3:52 p.m., at $0.743.
The last regular-session trade was $0.7432 at 3:59, and 7,437 shares traded at $0.7554 in the 4:00 minute. Only 51,598 shares traded in the regular session. For most minutes of the day, nothing traded at all.
4:05 p.m.: the headline
At 4:05 p.m. GlobeNewsWire ran: “Tempest Secures Exclusive Option to License Clinical-Stage CD7-Targeted Lentiviral In Vivo CAR-T Platform.” At 4:06 p.m. the company filed an 8-K.
The 4:05 minute traded 5,303 shares and ran from $0.8157 to a high of $0.8969. By 4:09 it was at $0.98 on 89,117 shares in that one minute.
After hours: $1.71
It pushed above $1 at 4:17 and traded 240,434 shares that minute. Then came the top. At 4:23 p.m. it hit $1.71, the high of the day, on 840,212 shares in one minute. The same minute closed at $1.35.
It fell fast from there. By 4:26 it was back near $1.08. It bounced to $1.30 at 4:31, but that was well below the $1.71 top, and it touched $0.89 at 4:44.
After that it traded mostly between about $0.92 and $1.31. By 5:09 p.m., more shares had traded on the day than exist in the whole float (8.33 million). It closed the session at 8 p.m. near $1.26 after a spike to $1.35 in the last minute.
After hours, 12.3 million shares traded. The regular session had only 51,598. The whole day came to 12.35 million, about 132 times the stock's normal volume.
What to take from it
- The regular session gave no sign of the after-hours volume. TPST drifted from $0.80 to $0.74 on thin volume, and the real action came after the bell.
- The biggest volume came after the bell. The last regular-session trade was $0.7432 at 3:59, the headline ran at 4:05 p.m., and by 4:09 the stock traded $0.98.
- The first spike was the high of the day. $1.71 printed at 4:23 p.m., and nothing traded that high for the rest of the evening.
Why it ran
News and SEC filings for TPST published between the previous session's close and the first minute TPST traded 20% above it, at 4:09 p.m. ET, newest first, from the same feeds the replay shows.
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8-K
-
Tempest Secures Exclusive Option to License Clinical-Stage CD7-Targeted Lentiviral In Vivo CAR-T Platform
News via Stock News API
How it traded
| Time (ET) | What happened | Watch it |
|---|---|---|
| 6:26 a.m. | Pre-market high, 0.8110 | |
| 6:26 a.m. | High of the day to the close, 0.8110 | |
| 9:30 a.m. | The open: 0.7990, up 1.9% from the previous close | |
| 3:59 p.m. | Last trade before the 4:00 p.m. close, 0.7432, 8.4% below the high | |
| 4:05 p.m. | News (GlobeNewsWire): Tempest Secures Exclusive Option to License Clinical-Stage CD7-Targeted Lentiviral In Vivo CAR-T Platform | |
| 4:06 p.m. | SEC filing 8-K: 8-K | |
| 4:09 p.m. | First trade 20% above the previous close of 0.7843 | |
| 5:09 p.m. | Volume since 4:00 a.m. passes the whole float, 8.33 million shares |
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
- From news to the move: the first trade 20% above the previous close came 2 minutes after the latest SEC filing before it (8-K, 4:06 p.m.).
- Volume, from the one-minute bars: 5,512 shares before the 9:30 a.m. open (0%), 3,738 in the first 30 minutes (0%), and 12.34 million in the rest of the day to 8 p.m. (100%).
- Float rotation, the volume since 4 a.m. against the float of 8.33 million shares: past it once at 5:09 p.m.
- Other days TPST met the small-cap rule in our recaps: 1, the latest on September 16, 2026.
Halts
The exchange's halt feed shows no halts for TPST that day.
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.
Trade this day
Replay TPST on September 15, 2026 in Hindsight Markets: the real tape, the order book and the halts, on a clock you control, and see where your orders would have filled.