Costco's SEC filing (Form 10-K) moved COST +1.89%
COST moved -0.13% in five minutes and +1.89% by market close — about 1890× Costco's median close-day move.
· SEC EDGAR · SEC filing · Form 10-K · Realized reaction, point-in-time, zero look-ahead.
Form 10-K COSTCO WHOLESALE CORP For: Sep 01
Via SEC EDGAR
How COST reacted after the announcement.
| Horizon | Reaction | COST median |
|---|---|---|
| 30 sec | -0.41% | — |
| 1 min | -0.33% | — |
| 5 min | -0.13% | — |
| 10 min | -0.03% | — |
| 30 min | +0.16% | -0.02% |
| 60 min | +0.90% | — |
| 90 min | +1.09% | — |
| 120 min | +1.32% | — |
| to close | +1.89% | +0.00% |
- +1%
- 59 min
- +2%
- never traded
- +3%
- never traded
- +5%
- never traded
- -1%
- never traded
- -2%
- never traded
- -3%
- never traded
- -5%
- never traded
A hatched rung is a threshold the price never touched inside the measured window — not a missing measurement. Most news never moves a large-cap by 5% either way, so a mostly empty ladder is the finding, not a gap in the data.
| Held for | Return |
|---|---|
| D+1 | +2.49% |
| D+2 | +0.75% |
| D+3 | +0.23% |
| D+4 | +0.31% |
| D+5 | +0.86% |
| 1M | +6.40% |
| 3M | +4.55% |
| 6M | +2.45% |
| 12M | +3.13% |
Each row is measured from the price at the news to that horizon independently, so the ladder is not cumulative and a later row can sit above an earlier one. “Available” is a date, not a gap: that horizon has not elapsed yet for this event, and it is computed from the event’s own timestamp rather than from the data. An em dash is the other case — the horizon passed and no return was recorded.
Five minutes after the news, COST had moved -0.13%; by the close it stood at +1.89% — the two readings disagree in direction, and the early move did not survive to the close.
Impact: Positive. Reaction = percent move vs. the price at the news timestamp. Sources below.
COST’s news landed in the pre-market window; the main session closed +1.89%.
- Mainprior session
- After-hours4:00 – 8:00 PM
- Overnightno tape
- Pre-market4:00 – 9:30 AM
- Main session9:30 AM – 4:00 PM
Segment widths are fixed, so two events on different days sit in comparable places. Hatched segments are real elapsed time with no tape to measure — the overnight halt is not a gap in the data. This event carries no intraday receipt time, so it is not pinned to a minute.
| Window | What it answers | Anchor price | Result | vs S&P 500 |
|---|---|---|---|---|
| All | From the news to the first main-session close, across every session in between. | 887.01re-anchored to the first print after the news | +2.49% | — |
| After-hours | The move between the closing bell and the overnight halt. | — | not measured | — |
| Pre-market | The move between the pre-market open and the opening bell. | — | not measured | — |
| Main | The move inside the regular session, from the news to the close. | 892.24the price at the news | +1.89% | +1.20% |
The main-session result is measured upstream against the price at the news; the all-sessions result is computed here from its own anchor and close, so the two can differ in the last decimal. The adjusted column subtracts the S&P 500’s move over the same main-session span — there is no index anchor for the all-sessions span, so that cell stays empty rather than borrowing this one. After-hours and pre-market are measured upstream but populate on a small minority of events, so this page does not request them. Those rows are unmeasured, not empty.
The same event measured across every session5
| Horizon | Reaction |
|---|---|
| 10 min | +0.09% |
| 30 min | +0.17% |
| 60 min | +0.20% |
| 90 min | +0.34% |
| 120 min | +0.38% |
Where this COST event came from, and what the tape did with it.
Costco filed Form 10-K with the SEC on Oct 9, 2024. It was one of 2 Costco headlines News Quantified labeled that day, so its measurement window overlaps with the others on a shared tape. The same session also carried Costco's "Costco Wholesale Corporation Reports September Sales Results", each measured on its own clock.
Against the price at the news timestamp, COST moved -0.13% after five minutes and +1.89% by the close — about 1890× Costco's median close-day move of +0.00% across 2,000+ events. Because several releases shared that day, their measurement windows overlap and no single headline cleanly owns the move.
This is the alert you’d have received.
Form 10-K COSTCO WHOLESALE CORP For: Sep 01
Track COST and you’ll get one email like this the next time it moves on news — the headline, the measured reaction, and how it compares to COST’s baseline. Nothing else.
Set up COST alerts →How this compares to COST’s usual reaction.
Across 2,000+ labeled events, COST’s median 30-minute reaction to all news is -0.02% (48% up); by the close it is +0.00%.
| Middle 50% of COST reactions | -0.42% to +0.30% |
|---|---|
| Median reaction (30-min) | -0.02% |
| This event | +0.16% |
| Measured reactions | 2,000+ |
Half of all Costco news events land between -0.42% and +0.30% at 30 minutes; this one is a single draw from that distribution.
You just saw one reaction. There are 26M+ more.
See the full COST reaction history →COST’s session ranged -0.49% to +1.99% against the price at the news.
935.9K shares against a 30-day average of 950.8K.
What the average share actually traded at across the session, rather than at any one print.
The close moved +1.89% against a 20-day average true range of 15.56. COST carries no market-cap or price-to-earnings figure on this record, and no short interest, so none is shown.
Email me when COST moves on news.
One email per qualifying move — the headline, the measured reaction, and how it compares to COST's baseline. Nothing else.
How comparable COST events have landed.
Across 5 other recent Costco SEC filing events, the median close-day reaction was -1.48%. Each is measured the same way, from its own news timestamp.
| Date | Headline | 5-min | To close |
|---|---|---|---|
| Form 8-K COSTCO WHOLESALE CORP For: Sep 24 | +2.36% | +3.92% | |
| Form 8-K COSTCO WHOLESALE CORP For: Jul 07 | -0.89% | -1.83% | |
| Form 11-K COSTCO WHOLESALE CORP For: Dec 31 | -0.10% | -1.24% | |
| Form 10-Q COSTCO WHOLESALE CORP For: May 10 | +0.08% | -1.48% | |
| Form S-3ASR COSTCO WHOLESALE CORP | +0.08% | -1.48% |
8 more COST events, each measured the same way.
Recent COST events, each with its measured reaction8
That same day, across the market8
Same measurement, same clock, different names — each headline measured from its own news timestamp, point-in-time.
Peer tickers, measured the same way4
Every US ticker is measured the same way, from its own news timestamp. Browse all tickers →
COST carried 1 other record that day.
Each was measured the same way, from its own timestamp.
| Record | Event | 5-min | To close |
|---|---|---|---|
| Costco Wholesale Corporation Reports September Sales Results | Press release | -0.34% | -1.69% |
How the numbers are made.
How was COST's -0.13% reaction measured?
From the news timestamp, not the trading day: News Quantified takes the last trade before this SEC filing (Form 10-K) as the base price and measures the move five minutes of trading later — point-in-time, zero look-ahead. The same clock produced the +1.89% to-close figure.
What is Costco's median reaction, and how does this event compare?
Costco's median is drawn from 2,000+ labeled events; at 30 minutes it sits at -0.02%, and +0.00% by the close. This event's move is one draw from that distribution — ordinary or outlier, the chart's median ticks show which.
2 Costco headlines shared Oct 9, 2024. Whose reaction is this?
Each of the 2 same-day Costco events is measured from its own timestamp, but their windows overlap on one tape, so we show the cluster rather than pretending a single headline owns the move.
Does +1.89% predict Costco's next reaction?
No. +1.89% is a realized fact about Oct 9, 2024, not a forecast. Past reactions describe a distribution; they say nothing certain about any future move.
How to cite this reaction.
News Quantified. "Form 10-K COSTCO WHOLESALE CORP For: Sep 01." COST realized price reaction, Oct 9, 2024. Retrieved from https://newsquantified.com/tickers/cost/news/form-10-k-costco-wholesale-for-sep-01-2024-10-09
Canonical URL: https://newsquantified.com/tickers/cost/news/form-10-k-costco-wholesale-for-sep-01-2024-10-09
Query this dataset via the API & MCP →