SIC 3572 Computer Storage Devices

Sandisk Corporation vs Western Digital Corporation

WatchlistSNDK / WDCPrices through Oct 22, 2026

Why these are rivals: #1 and #3 by market value ($199B vs $132B) with SEC SIC 3572 (Computer Storage Devices).

Rivals, but right now the price gap does not have a measured habit of closing, so there is no paper idea, whatever the gap.

Mean reversion: ADF t-statistic of the spread: -1.64 (needs <= -2.873 (5% critical value))

Business leadership

WDC is the larger business

Annual revenue reported to the SEC. Scale, not market share.

Year	SNDK	WDC	Larger
2024	$7.4B	$9.5B	WDC
2023	$6.7B	$6.3B	SNDK
2022	-	$18.8B	-
2021	-	$16.9B	-
2020	-	$16.7B	-

Revenue lead switched: 2024 to WDC. Market value: SNDK $199.3B, WDC $131.6B.

Stock leadership

SNDK is ahead now

Measured against the pair's own last 252 trading days.

SNDK leads WDC by 1.11 standard deviations: +47.6% over its usual price ratio. 0 lead switches in the last year.

Price change	3 mo	6 mo	12 mo
SNDK	-12.2%	+35.2%	+744.6%
WDC	-31.9%	-12.1%	+191.7%

Relationship

Not a measured twin today

Only these tests can make a pair tradable on paper.

Pass: Aligned sessions: 425 (needs >= 254)
Pass: Co-movement: daily return correlation, 252 sessions: 0.73 (needs >= 0.60)
Fail: Mean reversion: ADF t-statistic of the spread: -1.64 (needs <= -2.873 (5% critical value))
Pass: Speed: half-life of the spread, sessions: 49.07 (needs <= 63)
Data: Both stocks current

The twins over two years

Prices side by side, and the gap between them

SNDK Sandisk Corporation WDC Western Digital CorporationPrice index, 100 = 2025-02-13. Tint = which stock is ahead of the pair's usual 1-year relationship (z beyond +/-0.5).

Spread z-score: SNDK relative to WDC, against the 252 sessions before each day. Above 0: SNDK ahead; below 0: WDC ahead. Lines at +/-2 (idea) and +/-4 (stop).

Data table (425 sessions)

Date	SNDK index	WDC index	z	Ahead
2026-10-22	3502.58	684.65	+1.11	SNDK ahead
2026-10-21	3828.39	731.66	+1.18	SNDK ahead
2026-10-20	3792.72	704.23	+1.27	SNDK ahead
2026-10-19	3808.67	680.82	+1.38	SNDK ahead
2026-10-16	3609.17	641.75	+1.40	SNDK ahead
2026-10-15	3874.53	689.02	+1.41	SNDK ahead
2026-10-14	3898.17	703.80	+1.38	SNDK ahead
2026-10-13	4117.58	735.91	+1.41	SNDK ahead
2026-10-12	4131.47	747.95	+1.38	SNDK ahead
2026-10-09	4393.94	767.94	+1.49	SNDK ahead
2026-10-08	4470.72	760.27	+1.57	SNDK ahead
2026-10-07	4701.17	783.67	+1.63	SNDK ahead
2026-10-06	4612.39	794.54	+1.55	SNDK ahead
2026-10-05	4733.78	853.69	+1.43	SNDK ahead
2026-10-02	4777.75	802.75	+1.62	SNDK ahead
2026-10-01	4965.81	894.13	+1.45	SNDK ahead
2026-09-30	4833.03	878.47	+1.43	SNDK ahead
2026-09-29	4804.89	876.57	+1.42	SNDK ahead
2026-09-28	4758.03	876.09	+1.40	SNDK ahead
2026-09-25	4938.33	883.01	+1.49	SNDK ahead
2026-09-24	4871.17	870.45	+1.50	SNDK ahead
2026-09-23	5046.03	915.64	+1.46	SNDK ahead
2026-09-22	5241.78	898.07	+1.62	SNDK ahead
2026-09-21	4907.33	866.31	+1.55	SNDK ahead
2026-09-18	4977.28	853.15	+1.63	SNDK ahead
2026-09-17	4484.42	819.34	+1.48	SNDK ahead
2026-09-16	4222.14	806.00	+1.38	SNDK ahead
2026-09-15	4252.49	796.32	+1.43	SNDK ahead
2026-09-14	4311.08	825.27	+1.38	SNDK ahead
2026-09-11	4537.08	864.40	+1.40	SNDK ahead
2026-09-10	4701.64	890.98	+1.42	SNDK ahead
2026-09-09	4900.47	932.24	+1.41	SNDK ahead
2026-09-08	4827.75	922.62	+1.41	SNDK ahead
2026-09-04	4833.33	903.60	+1.46	SNDK ahead
2026-09-03	4319.42	853.55	+1.33	SNDK ahead
2026-09-02	4315.00	867.72	+1.29	SNDK ahead
2026-09-01	4269.08	870.70	+1.26	SNDK ahead
2026-08-31	4351.94	870.91	+1.31	SNDK ahead
2026-08-28	4124.94	888.11	+1.14	SNDK ahead
2026-08-27	4124.86	893.04	+1.13	SNDK ahead
2026-08-26	4164.92	906.34	+1.13	SNDK ahead
2026-08-25	4113.25	871.30	+1.19	SNDK ahead
2026-08-24	4147.56	841.59	+1.28	SNDK ahead
2026-08-21	4433.56	888.10	+1.32	SNDK ahead
2026-08-20	4446.17	906.67	+1.28	SNDK ahead
2026-08-19	4357.97	893.22	+1.27	SNDK ahead
2026-08-18	4516.06	959.07	+1.20	SNDK ahead
2026-08-17	4963.47	1036.10	+1.24	SNDK ahead
2026-08-14	4558.64	983.51	+1.18	SNDK ahead
2026-08-13	4244.75	941.93	+1.13	SNDK ahead
2026-08-12	3734.14	877.77	+1.02	SNDK ahead
2026-08-11	3530.69	846.52	+0.98	SNDK ahead
2026-08-10	3438.67	847.31	+0.93	SNDK ahead
2026-08-07	3367.25	839.50	+0.91	SNDK ahead
2026-08-06	3496.06	872.79	+0.92	SNDK ahead
2026-08-05	3751.39	1003.55	+0.79	SNDK ahead
2026-08-04	3965.61	1060.36	+0.79	SNDK ahead
2026-08-03	3577.86	1019.11	+0.68	SNDK ahead
2026-07-31	3374.53	1053.17	+0.51	SNDK ahead
2026-07-30	3555.44	1030.36	+0.65	SNDK ahead
2026-07-29	2821.92	893.12	+0.49	near the usual relationship
2026-07-28	3044.72	895.96	+0.64	SNDK ahead
2026-07-27	3550.64	962.48	+0.79	SNDK ahead
2026-07-24	3990.44	1004.77	+0.94	SNDK ahead
2026-07-23	4473.14	1079.19	+1.02	SNDK ahead
2026-07-22	4442.42	1076.04	+1.02	SNDK ahead
2026-07-21	4415.00	1060.03	+1.04	SNDK ahead
2026-07-20	3863.75	942.18	+1.02	SNDK ahead
2026-07-17	3763.39	922.46	+1.02	SNDK ahead
2026-07-16	3919.67	902.34	+1.14	SNDK ahead
2026-07-15	4486.11	993.25	+1.22	SNDK ahead
2026-07-14	4882.83	1088.89	+1.22	SNDK ahead
2026-07-13	4649.92	1073.88	+1.16	SNDK ahead
2026-07-10	5322.00	1126.13	+1.33	SNDK ahead
2026-07-09	5161.86	1117.37	+1.30	SNDK ahead
2026-07-08	4797.72	1063.73	+1.26	SNDK ahead
2026-07-07	4493.61	1028.55	+1.22	SNDK ahead
2026-07-06	4845.64	1116.23	+1.21	SNDK ahead
2026-07-02	4847.22	1041.88	+1.35	SNDK ahead
2026-07-01	5645.06	1156.65	+1.45	SNDK ahead
2026-06-30	6315.92	1234.64	+1.54	SNDK ahead
2026-06-29	5695.53	1260.08	+1.33	SNDK ahead
2026-06-26	5807.53	1133.60	+1.57	SNDK ahead
2026-06-25	6486.11	1305.53	+1.53	SNDK ahead
2026-06-24	5317.94	1244.52	+1.27	SNDK ahead
2026-06-23	5454.44	1296.56	+1.25	SNDK ahead
2026-06-22	6315.92	1416.15	+1.37	SNDK ahead
2026-06-18	6068.75	1442.46	+1.27	SNDK ahead
2026-06-17	5441.11	1376.54	+1.17	SNDK ahead
2026-06-16	5532.08	1316.52	+1.29	SNDK ahead
2026-06-15	5855.17	1263.27	+1.48	SNDK ahead
2026-06-12	5500.28	1088.13	+1.65	SNDK ahead
2026-06-11	5226.42	1023.11	+1.69	SNDK ahead
2026-06-10	4564.53	947.34	+1.60	SNDK ahead
2026-06-09	4573.72	1000.75	+1.51	SNDK ahead
2026-06-08	4561.11	1018.55	+1.49	SNDK ahead
2026-06-05	4331.44	989.15	+1.46	SNDK ahead
2026-06-04	4888.00	1112.44	+1.48	SNDK ahead
2026-06-03	5087.50	1148.41	+1.51	SNDK ahead
2026-06-02	4767.67	1088.47	+1.50	SNDK ahead
2026-06-01	4892.86	1055.80	+1.62	SNDK ahead
2026-05-29	4708.28	1026.83	+1.61	SNDK ahead
2026-05-28	4560.11	1026.77	+1.57	SNDK ahead
2026-05-27	4416.50	1025.65	+1.53	SNDK ahead
2026-05-26	4415.42	1014.15	+1.56	SNDK ahead
2026-05-22	4107.47	936.11	+1.59	SNDK ahead
2026-05-21	4284.00	940.32	+1.68	SNDK ahead
2026-05-20	3868.22	888.44	+1.61	SNDK ahead
2026-05-19	3842.47	881.06	+1.63	SNDK ahead
2026-05-18	3702.81	886.63	+1.56	SNDK ahead
2026-05-15	3910.03	931.74	+1.59	SNDK ahead
2026-05-14	3840.89	945.52	+1.54	SNDK ahead
2026-05-13	4020.08	955.07	+1.62	SNDK ahead
2026-05-12	4033.39	944.73	+1.67	SNDK ahead
2026-05-11	4298.78	997.10	+1.70	SNDK ahead
2026-05-08	4339.83	927.84	+1.88	SNDK ahead
2026-05-07	3722.11	896.74	+1.67	SNDK ahead
2026-05-06	3916.61	933.93	+1.70	SNDK ahead
2026-05-05	3906.44	899.35	+1.79	SNDK ahead
2026-05-04	3488.50	855.08	+1.68	SNDK ahead
2026-05-01	3297.22	834.13	+1.64	SNDK ahead
2026-04-30	3045.86	839.92	+1.48	SNDK ahead
2026-04-29	2956.14	797.86	+1.54	SNDK ahead
2026-04-28	2784.31	755.78	+1.54	SNDK ahead
2026-04-27	2972.78	774.61	+1.64	SNDK ahead
2026-04-24	2749.72	780.93	+1.48	SNDK ahead
2026-04-23	2590.08	779.23	+1.38	SNDK ahead
2026-04-22	2719.64	752.13	+1.56	SNDK ahead
2026-04-21	2509.69	741.90	+1.44	SNDK ahead
2026-04-20	2536.17	723.15	+1.53	SNDK ahead
2026-04-17	2558.31	720.08	+1.57	SNDK ahead
2026-04-16	2554.08	699.14	+1.64	SNDK ahead
2026-04-15	2477.00	705.54	+1.58	SNDK ahead
2026-04-14	2623.50	707.90	+1.70	SNDK ahead
2026-04-13	2645.83	676.86	+1.84	SNDK ahead
2026-04-10	2366.03	663.85	+1.66	SNDK ahead
2026-04-09	2365.47	653.12	+1.71	SNDK ahead
2026-04-08	2169.17	654.86	+1.53	SNDK ahead
2026-04-07	1974.44	603.02	+1.52	SNDK ahead
2026-04-06	2012.86	587.92	+1.63	SNDK ahead
2026-04-02	1948.86	570.18	+1.64	SNDK ahead
2026-04-01	1924.25	575.51	+1.61	SNDK ahead
2026-03-31	1764.83	522.86	+1.65	SNDK ahead
2026-03-30	1590.28	486.48	+1.59	SNDK ahead
2026-03-27	1710.64	532.23	+1.56	SNDK ahead
2026-03-26	1675.47	528.38	+1.55	SNDK ahead
2026-03-25	1882.94	572.44	+1.64	SNDK ahead
2026-03-24	1951.33	581.93	+1.70	SNDK ahead
2026-03-23	1951.36	569.83	+1.76	SNDK ahead
2026-03-20	1971.42	566.56	+1.82	SNDK ahead
2026-03-19	2144.69	612.62	+1.85	SNDK ahead
2026-03-18	2093.58	589.37	+1.90	SNDK ahead
2026-03-17	2000.47	606.59	+1.75	SNDK ahead
2026-03-16	1954.53	553.24	+1.92	SNDK ahead
2026-03-13	1837.83	526.34	+1.92	SNDK ahead
2026-03-12	1718.94	504.86	+1.88	SNDK ahead
2026-03-11	1820.64	519.61	+1.96	SNDK ahead
2026-03-10	1719.14	514.60	+1.87	SNDK ahead
2026-03-09	1635.36	506.56	+1.81	SNDK ahead
2026-03-06	1464.81	474.07	+1.72	SNDK ahead
2026-03-05	1571.08	500.70	+1.77	SNDK ahead
2026-03-04	1664.06	505.09	+1.91	SNDK ahead
2026-03-03	1570.58	484.43	+1.89	SNDK ahead
2026-03-02	1719.67	522.06	+1.96	SNDK ahead
2026-02-27	1764.89	540.66	+1.96	SNDK ahead
2026-02-26	1810.83	545.59	+2.02	SNDK ahead
2026-02-25	1756.61	562.40	+1.89	SNDK ahead
2026-02-24	1773.67	523.01	+2.13	SNDK ahead
2026-02-23	1851.36	542.05	+2.18	SNDK ahead
2026-02-20	1805.47	551.91	+2.09	SNDK ahead
2026-02-19	1725.25	550.27	+2.01	SNDK ahead
2026-02-18	1667.78	573.25	+1.83	SNDK ahead
2026-02-17	1640.53	549.18	n/a
2026-02-13	1740.44	544.29	n/a
2026-02-12	1750.81	549.16	n/a
2026-02-11	1664.83	529.14	n/a
2026-02-10	1504.56	507.53	n/a
2026-02-09	1620.56	552.82	n/a
2026-02-06	1660.97	546.23	n/a
2026-02-05	1600.56	502.95	n/a
2026-02-04	1623.75	520.77	n/a
2026-02-03	1931.97	561.03	n/a
2026-02-02	1847.89	522.35	n/a
2026-01-30	1600.69	483.69	n/a
2026-01-29	1498.06	538.17	n/a
2026-01-28	1465.64	540.66	n/a
2026-01-27	1337.31	488.39	n/a
2026-01-26	1307.78	465.56	n/a
2026-01-23	1316.19	456.94	n/a
2026-01-22	1398.44	470.28	n/a
2026-01-21	1392.47	467.59	n/a
2026-01-20	1258.67	431.00	n/a
2026-01-16	1148.94	428.18	n/a
2026-01-15	1136.78	429.32	n/a
2026-01-14	1077.25	415.59	n/a
2026-01-13	1082.81	413.66	n/a
2026-01-12	1081.31	410.07	n/a
2026-01-09	1048.36	387.49	n/a
2026-01-08	929.28	362.78	n/a
2026-01-07	982.11	386.37	n/a
2026-01-06	971.19	424.06	n/a
2026-01-05	761.33	363.17	n/a
2026-01-02	764.56	362.82	n/a
2025-12-31	659.39	333.00	n/a
2025-12-30	667.28	340.32	n/a
2025-12-29	678.47	347.32	n/a
2025-12-26	694.58	350.92	n/a
2025-12-24	694.67	347.09	n/a
2025-12-23	680.28	344.56	n/a
2025-12-22	669.58	341.68	n/a
2025-12-19	660.03	350.03	n/a
2025-12-18	609.61	338.29	n/a
2025-12-17	574.53	321.38	n/a
2025-12-16	581.42	337.45	n/a
2025-12-15	560.75	332.55	n/a
2025-12-12	572.72	340.86	n/a
2025-12-11	671.14	361.86	n/a
2025-12-10	646.83	351.71	n/a
2025-12-09	609.61	327.72	n/a
2025-12-08	626.31	328.18	n/a
2025-12-05	634.64	326.46	n/a
2025-12-04	592.53	311.21	n/a
2025-12-03	539.94	300.75	n/a
2025-12-02	570.42	309.26	n/a
2025-12-01	583.81	316.12	n/a
2025-11-28	620.22	315.72	n/a
2025-11-26	597.33	304.91	n/a
2025-11-25	612.50	300.41	n/a
2025-11-24	630.44	291.75	n/a
2025-11-21	556.31	269.05	n/a
2025-11-20	544.33	271.06	n/a
2025-11-19	683.22	297.62	n/a
2025-11-18	680.36	295.48	n/a
2025-11-17	738.56	314.01	n/a
2025-11-14	706.00	305.08	n/a
2025-11-13	676.58	303.79	n/a
2025-11-12	786.39	321.09	n/a
2025-11-11	754.39	328.59	n/a
2025-11-10	744.31	336.77	n/a
2025-11-07	665.22	314.99	n/a
2025-11-06	576.92	316.24	n/a
2025-11-05	601.39	309.47	n/a
2025-11-04	540.47	294.16	n/a
2025-11-03	575.03	305.45	n/a
2025-10-31	553.69	290.36	n/a
2025-10-30	543.94	267.00	n/a
2025-10-29	567.67	273.29	n/a
2025-10-28	487.58	241.47	n/a
2025-10-27	490.25	244.85	n/a
2025-10-24	517.11	250.19	n/a
2025-10-23	464.03	243.02	n/a
2025-10-22	408.19	232.87	n/a
2025-10-21	414.69	234.68	n/a
2025-10-20	411.22	234.92	n/a
2025-10-17	389.33	243.94	n/a
2025-10-16	400.75	243.40	n/a
2025-10-15	400.83	232.81	n/a
2025-10-14	353.58	218.68	n/a
2025-10-13	373.92	229.76	n/a
2025-10-10	324.75	223.11	n/a
2025-10-09	360.22	231.38	n/a
2025-10-08	366.33	234.24	n/a
2025-10-07	335.97	231.82	n/a
2025-10-06	336.58	242.17	n/a
2025-10-03	356.69	253.82	n/a
2025-10-02	344.83	253.72	n/a
2025-10-01	336.44	252.43	n/a
2025-09-30	311.67	232.08	n/a
2025-09-29	315.28	225.66	n/a
2025-09-26	269.78	206.60	n/a
2025-09-25	261.92	207.24	n/a
2025-09-24	277.31	212.03	n/a
2025-09-23	295.56	213.11	n/a
2025-09-22	285.89	217.29	n/a
2025-09-19	283.92	206.12	n/a
2025-09-18	274.64	203.25	n/a
2025-09-17	261.03	195.12	n/a
2025-09-16	254.31	199.27	n/a
2025-09-15	250.25	197.92	n/a
2025-09-12	239.25	188.78	n/a
2025-09-11	234.17	185.86	n/a
2025-09-10	205.33	183.67	n/a
2025-09-09	195.86	182.75	n/a
2025-09-08	195.82	180.33	n/a
2025-09-05	190.42	177.91	n/a
2025-09-04	173.61	174.92	n/a
2025-09-03	147.25	166.24	n/a
2025-09-02	141.86	158.33	n/a
2025-08-29	145.75	155.30	n/a
2025-08-28	141.31	158.58	n/a
2025-08-27	134.56	155.93	n/a
2025-08-26	131.53	154.08	n/a
2025-08-25	129.94	153.13	n/a
2025-08-22	128.81	148.78	n/a
2025-08-21	126.39	144.32	n/a
2025-08-20	123.33	146.21	n/a
2025-08-19	123.83	146.64	n/a
2025-08-18	126.44	147.47	n/a
2025-08-15	123.72	145.09	n/a
2025-08-14	129.67	147.37	n/a
2025-08-13	130.58	147.04	n/a
2025-08-12	130.08	146.73	n/a
2025-08-11	120.47	144.28	n/a
2025-08-08	123.17	144.92	n/a
2025-08-07	113.03	143.89	n/a
2025-08-06	116.94	142.62	n/a
2025-08-05	116.47	146.60	n/a
2025-08-04	118.08	149.40	n/a
2025-08-01	114.81	147.97	n/a
2025-07-31	119.22	152.11	n/a
2025-07-30	120.53	138.07	n/a
2025-07-29	119.25	136.49	n/a
2025-07-28	116.36	133.35	n/a
2025-07-25	118.00	133.03	n/a
2025-07-24	116.83	133.42	n/a
2025-07-23	119.44	134.00	n/a
2025-07-22	114.89	129.63	n/a
2025-07-21	115.58	132.87	n/a
2025-07-18	117.19	131.44	n/a
2025-07-17	115.33	129.55	n/a
2025-07-16	114.89	128.60	n/a
2025-07-15	118.67	130.54	n/a
2025-07-14	118.00	129.38	n/a
2025-07-11	128.03	127.85	n/a
2025-07-10	130.42	125.76	n/a
2025-07-09	128.33	124.95	n/a
2025-07-08	128.25	123.75	n/a
2025-07-07	125.61	126.06	n/a
2025-07-03	128.92	127.73	n/a
2025-07-02	128.36	127.15	n/a
2025-07-01	124.89	123.40	n/a
2025-06-30	125.97	123.69	n/a
2025-06-27	130.97	122.34	n/a
2025-06-26	131.78	122.76	n/a
2025-06-25	131.25	120.91	n/a
2025-06-24	131.50	119.98	n/a
2025-06-23	130.42	116.71	n/a
2025-06-20	129.39	114.61	n/a
2025-06-18	129.50	114.41	n/a
2025-06-17	122.47	113.22	n/a
2025-06-16	122.81	110.97	n/a
2025-06-13	118.06	107.67	n/a
2025-06-12	114.72	107.82	n/a
2025-06-11	111.75	107.61	n/a
2025-06-10	115.53	108.15	n/a
2025-06-09	116.17	110.22	n/a
2025-06-06	108.75	107.18	n/a
2025-06-05	108.67	106.41	n/a
2025-06-04	110.61	105.21	n/a
2025-06-03	107.33	103.94	n/a
2025-06-02	103.69	100.88	n/a
2025-05-30	104.69	99.65	n/a
2025-05-29	107.22	101.58	n/a
2025-05-28	107.17	101.19	n/a
2025-05-27	106.06	100.17	n/a
2025-05-23	103.56	97.00	n/a
2025-05-22	105.11	96.34	n/a
2025-05-21	107.22	95.66	n/a
2025-05-20	111.61	97.87	n/a
2025-05-19	107.72	98.04	n/a
2025-05-16	112.33	96.63	n/a
2025-05-15	112.61	96.17	n/a
2025-05-14	116.47	95.10	n/a
2025-05-13	116.67	94.74	n/a
2025-05-12	114.64	90.02	n/a
2025-05-09	104.83	85.25	n/a
2025-05-08	101.83	85.63	n/a
2025-05-07	97.14	85.63	n/a
2025-05-06	93.97	85.61	n/a
2025-05-05	96.14	87.04	n/a
2025-05-02	95.56	86.39	n/a
2025-05-01	90.53	84.96	n/a
2025-04-30	89.19	84.78	n/a
2025-04-29	91.50	78.52	n/a
2025-04-28	89.64	79.08	n/a
2025-04-25	91.25	78.83	n/a
2025-04-24	89.69	77.65	n/a
2025-04-23	84.33	72.87	n/a
2025-04-22	82.28	70.90	n/a
2025-04-21	82.81	69.51	n/a
2025-04-17	86.92	70.57	n/a
2025-04-16	88.97	68.85	n/a
2025-04-15	92.31	69.45	n/a
2025-04-14	93.19	69.24	n/a
2025-04-11	88.81	66.50	n/a
2025-04-10	86.32	67.40	n/a
2025-04-09	101.61	70.17	n/a
2025-04-08	89.86	60.99	n/a
2025-04-07	87.44	60.23	n/a
2025-04-04	83.64	59.03	n/a
2025-04-03	106.28	66.01	n/a
2025-04-02	132.42	80.76	n/a
2025-04-01	133.64	79.04	n/a
2025-03-31	132.25	78.15	n/a
2025-03-28	136.03	78.52	n/a
2025-03-27	146.89	81.01	n/a
2025-03-26	146.17	82.38	n/a
2025-03-25	145.00	83.87	n/a
2025-03-24	147.19	85.65	n/a
2025-03-21	149.89	84.39	n/a
2025-03-20	156.14	86.04	n/a
2025-03-19	156.47	86.79	n/a
2025-03-18	156.72	85.71	n/a
2025-03-17	154.58	86.50	n/a
2025-03-14	152.28	86.08	n/a
2025-03-13	134.56	81.24	n/a
2025-03-12	140.11	83.04	n/a
2025-03-11	144.89	80.80	n/a
2025-03-10	147.22	78.36	n/a
2025-03-07	141.67	80.61	n/a
2025-03-06	129.17	80.12	n/a
2025-03-05	134.64	85.44	n/a
2025-03-04	135.25	86.27	n/a
2025-03-03	139.75	90.87	n/a
2025-02-28	130.14	94.58	n/a
2025-02-27	125.44	93.17	n/a
2025-02-26	129.39	96.96	n/a
2025-02-25	133.78	94.85	n/a
2025-02-24	135.00	94.76	n/a
2025-02-21	139.92	101.69	n/a
2025-02-20	134.06	105.52	n/a
2025-02-19	127.78	105.83	n/a
2025-02-18	130.97	106.62	n/a
2025-02-14	101.81	101.23	n/a
2025-02-13	100.00	100.00	n/a

No one-day company-specific move of 4+ standard deviations in this window. Upcoming earnings: SNDK Oct 29, 2026 (after-hours).

Paired trades

The shared paper book and the replay, kept apart

Forward paper record

No paper position on this pair yet.

Historical simulation (a diagnostic, same rules)

No simulated trade through Oct 20, 2026: the pair rarely passed every test while 2 standard deviations apart.

Per $10,000 a leg. A replay on today's companies cannot prove an edge.

The companies

SNDK and WDC at a glance

SNDK Sandisk Corporation

Listing: Nasdaq · SEC CIK 2023554
Industry: Electronic Components · SIC 3572 Computer Storage Devices
Market value: $199.3B
Price history: 425 daily closes, Feb 13, 2025 to Oct 22, 2026

WDC Western Digital Corporation

Listing: Nasdaq · SEC CIK 106040
Industry: Electronic Components · SIC 3572 Computer Storage Devices
Market value: $131.6B
Price history: 2,521 daily closes, Oct 12, 2016 to Oct 22, 2026

Daily prices: Nasdaq.com. Filings and industry codes: SEC EDGAR. Earnings dates: Nasdaq earnings calendar.

All pairs →

Pair	Status	Ahead now	Industry
STX / WDC	Watchlist	STX by 1.03 sd	SIC 3572 Computer Storage Devices
SNDK / STX	Watchlist	SNDK by 0.85 sd	Electronic Components

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Paper only: hypothetical paired positions with modelled costs. No broker, no orders, no real money. A historical simulation is a diagnostic, not proof of an edge. Not investment advice.