Amazon: a 8.4σ rise on 31 July 2026

Recorded 7 October 2026

On 31 July 2026 Amazon rose 15.32% close to close, 8.4 times its typical daily move of 1.82% over the 20 sessions before it: larger than every one of the 19 sessions on record before it. 12 other instruments of the 148 measured that day moved 2σ or more.

The day

Daily closes, as recorded the night after

Move: +15.32%
Size: +8.4σ
Typical day before it: 1.82%
Close: 271.58
Previous close, 30 July 2026: 235.5
Since, to 21 October 2026: −3.39%

Amazon, the 30 sessions to 31 July 2026

Daily closes; the last point is the quake

Show values

Amazon, the 30 sessions to 31 July 2026
Point	AMZN
17 Jun 2026	238
18 Jun 2026	244
22 Jun 2026	233
23 Jun 2026	234
24 Jun 2026	234
25 Jun 2026	227
26 Jun 2026	233
29 Jun 2026	240
30 Jun 2026	238
1 Jul 2026	242
2 Jul 2026	243
6 Jul 2026	244
7 Jul 2026	246
8 Jul 2026	244
9 Jul 2026	247
10 Jul 2026	245
13 Jul 2026	247
14 Jul 2026	247
15 Jul 2026	255
16 Jul 2026	250
17 Jul 2026	247
20 Jul 2026	250
21 Jul 2026	248
22 Jul 2026	245
23 Jul 2026	234
24 Jul 2026	232
27 Jul 2026	231
28 Jul 2026	231
29 Jul 2026	227
30 Jul 2026	236
31 Jul 2026	272

The same day

Other quakes on 31 July 2026

Instrument	Move	Size
Novo Nordisk NVO	−8.78%	−5.0σ
Apple AAPL	−7.35%	−4.0σ
KOSPI KOSPI	+17.91%	+3.5σ

Amazon's other quakes

On record, newest first

19 October 2026: +4.98%, +3.2σ
23 July 2026: −4.57%, −3.0σ

How it is measured

The move is the close-to-close return; its size is that return divided by the standard deviation of Amazon's previous 20 daily returns. A quake is 3σ or more. This record was made the night after the day finished trading and has not been changed since. The live chart is on Amazon's page; the last few months of every market's daily moves are on the volatility terrain, and every quake on record is in the quake archive.