Costco's SEC filing (Form SD) moved COST -3.07%
COST moved -1.37% in five minutes and -3.07% by market close — about 3066× Costco's median close-day move.
· SEC EDGAR · SEC filing · Form SD · Realized reaction, point-in-time, zero look-ahead.
Form SD COSTCO WHOLESALE CORP
Via SEC EDGAR
How COST reacted after the announcement.
| Horizon | Reaction | COST median |
|---|---|---|
| 30 sec | +0.41% | — |
| 1 min | +0.79% | — |
| 5 min | -1.37% | — |
| 10 min | -1.96% | — |
| 30 min | -3.96% | -0.02% |
| 60 min | -2.99% | — |
| 90 min | -3.73% | — |
| 120 min | -3.75% | — |
| to close | -3.07% | +0.00% |
- +1%
- 1 min
- +2%
- never traded
- +3%
- never traded
- +5%
- never traded
- -1%
- 4 min
- -2%
- 9 min
- -3%
- 14 min
- -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 | -3.46% |
| D+2 | -4.49% |
| D+3 | -3.67% |
| D+4 | -2.91% |
| D+5 | -1.84% |
| 1M | -4.44% |
| 3M | -4.56% |
| 6M | |
| 12M |
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 -1.37%; by the close it stood at -3.07% — the two readings agree in direction.
Impact: Negative. 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 -3.07%.
- 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. | 990.62re-anchored to the first print after the news | -3.46% | — |
| 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. | 986.57the price at the news | -3.07% | -3.14% |
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 session8
| Horizon | Reaction |
|---|---|
| 30 sec | +0.00% |
| 1 min | -0.01% |
| 5 min | -0.05% |
| 10 min | -0.01% |
| 30 min | +0.03% |
| 60 min | +0.05% |
| 90 min | -0.47% |
| 120 min | -0.17% |
Where this COST event came from, and what the tape did with it.
Costco made an SEC filing on May 29, 2026. It was the only Costco headline News Quantified labeled that day.
Against the price at the news timestamp, COST moved -1.37% after five minutes and -3.07% by the close — about 3066× Costco's median close-day move of +0.00% across 2,000+ events.
This is the alert you’d have received.
Form SD COSTCO WHOLESALE CORP
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 | -3.96% |
| 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 -4.17% to +1.24% against the price at the news.
4.6M shares against a 30-day average of 1.2M.
What the average share actually traded at across the session, rather than at any one print.
The close moved -3.07% against a 20-day average true range of 22.44. 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
| Ticker | Headline | 5-min | To close |
|---|---|---|---|
| V | Multiple Independent Reviews Recognize TacticalPay as a Top Firearms Payment Processor and Gun Store POS System | -1.10% | -1.52% |
| ORCL | Form SD ORACLE CORP | -0.98% | +6.91% |
| WMT | Form SD Walmart Inc. | +0.37% | -0.25% |
| WMT | Form 10-Q Walmart Inc. For: Apr 30 | +0.37% | -0.25% |
| META | Form 8-K Meta Platforms, Inc. For: May 27 | -1.10% | -4.58% |
| TSLA | Form SD Tesla, Inc. | -0.66% | -2.70% |
| AMZN | Form SD AMAZON COM INC | -0.15% | -1.85% |
| XOM | Form 8-K EXXON MOBIL CORP For: May 27 | +0.19% | -0.24% |
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 →
How the numbers are made.
How was COST's -1.37% reaction measured?
From the news timestamp, not the trading day: News Quantified takes the last trade before this SEC filing (Form SD) as the base price and measures the move five minutes of trading later — point-in-time, zero look-ahead. The same clock produced the -3.07% 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.
Only one Costco headline was labeled May 29, 2026. How is it isolated?
It was the only Costco headline labeled that day, so its window has no same-day overlap — the move is measured cleanly from its own timestamp.
Does -3.07% predict Costco's next reaction?
No. -3.07% is a realized fact about May 29, 2026, not a forecast. Past reactions describe a distribution; they say nothing certain about any future move.
How to cite this reaction.
News Quantified. "Form SD COSTCO WHOLESALE CORP." COST realized price reaction, May 29, 2026. Retrieved from https://newsquantified.com/tickers/cost/news/form-sd-costco-wholesale-2026-05-29
Canonical URL: https://newsquantified.com/tickers/cost/news/form-sd-costco-wholesale-2026-05-29
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