Seagate Technology Holdings PLC Ordinary Shares (Ireland) vs Western Digital Corporation
WatchlistSTX / WDCPrices through Oct 22, 2026
Why these are rivals: #2 and #3 by market value ($151B 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: -1.67 (needs <= -2.873 (5% critical value))
Business leadership
WDC is the larger business
Annual revenue reported to the SEC. Scale, not market share.
| Year | STX | WDC | Larger |
|---|---|---|---|
| 2024 | $9.1B | $9.5B | WDC |
| 2023 | $7.4B | $6.3B | STX |
| 2022 | $11.7B | $18.8B | WDC |
| 2021 | $10.7B | $16.9B | WDC |
| 2020 | $10.5B | $16.7B | WDC |
Revenue lead switched: 2023 to STX, 2024 to WDC. Market value: STX $151.1B, WDC $131.6B.
Stock leadership
STX is ahead now
Measured against the pair's own last 252 trading days.
STX leads WDC by 1.03 standard deviations: +11.2% over its usual price ratio. 1 lead switch in the last year.
| Price change | 3 mo | 6 mo | 12 mo |
|---|---|---|---|
| STX | -24.6% | +9.3% | +199.3% |
| 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: 2521 (needs >= 254)
- Pass
- Co-movement: daily return correlation, 252 sessions: 0.88 (needs >= 0.60)
- Fail
- Mean reversion: ADF t-statistic of the spread: -1.67 (needs <= -2.873 (5% critical value))
- Pass
- Speed: half-life of the spread, sessions: 26.57 (needs <= 63)
- Data
- Both stocks current
The twins over two years
Prices side by side, and the gap between them
STX Seagate Technology Holdings PLC Ordinary Shares (Ireland) WDC Western Digital CorporationPrice index, 100 = 2024-10-18. Tint = which stock is ahead of the pair's usual 1-year relationship (z beyond +/-0.5).
Spread z-score: STX relative to WDC, against the 252 sessions before each day. Above 0: STX ahead; below 0: WDC ahead. Lines at +/-2 (idea) and +/-4 (stop).
Data table (504 sessions)
| Date | STX index | WDC index | z | Ahead |
|---|---|---|---|---|
| 2026-10-22 | 572.73 | 690.06 | +1.03 | STX ahead |
| 2026-10-21 | 621.56 | 737.44 | +1.19 | STX ahead |
| 2026-10-20 | 602.15 | 709.80 | +1.25 | STX ahead |
| 2026-10-19 | 589.38 | 686.20 | +1.38 | STX ahead |
| 2026-10-16 | 569.93 | 646.83 | +1.63 | STX ahead |
| 2026-10-15 | 616.13 | 694.46 | +1.71 | STX ahead |
| 2026-10-14 | 636.41 | 709.37 | +1.82 | STX ahead |
| 2026-10-13 | 666.43 | 741.73 | +1.85 | STX ahead |
| 2026-10-12 | 671.82 | 753.87 | +1.77 | STX ahead |
| 2026-10-09 | 698.36 | 774.01 | +1.91 | STX ahead |
| 2026-10-08 | 691.07 | 766.28 | +1.91 | STX ahead |
| 2026-10-07 | 720.27 | 789.87 | +2.03 | STX ahead |
| 2026-10-06 | 718.54 | 800.82 | +1.87 | STX ahead |
| 2026-10-05 | 791.20 | 860.44 | +2.12 | STX ahead |
| 2026-10-02 | 757.22 | 809.10 | +2.31 | STX ahead |
| 2026-10-01 | 843.36 | 901.20 | +2.31 | STX ahead |
| 2026-09-30 | 822.64 | 885.41 | +2.25 | STX ahead |
| 2026-09-29 | 814.71 | 883.50 | +2.17 | STX ahead |
| 2026-09-28 | 821.90 | 883.02 | +2.26 | STX ahead |
| 2026-09-25 | 817.72 | 889.99 | +2.13 | STX ahead |
| 2026-09-24 | 807.99 | 877.33 | +2.14 | STX ahead |
| 2026-09-23 | 823.99 | 922.88 | +1.82 | STX ahead |
| 2026-09-22 | 820.41 | 905.17 | +1.96 | STX ahead |
| 2026-09-21 | 782.49 | 873.16 | +1.84 | STX ahead |
| 2026-09-18 | 765.96 | 859.89 | +1.77 | STX ahead |
| 2026-09-17 | 716.31 | 825.82 | +1.49 | STX ahead |
| 2026-09-16 | 698.52 | 812.37 | +1.39 | STX ahead |
| 2026-09-15 | 688.38 | 802.61 | +1.36 | STX ahead |
| 2026-09-14 | 718.47 | 831.80 | +1.42 | STX ahead |
| 2026-09-11 | 740.43 | 871.23 | +1.25 | STX ahead |
| 2026-09-10 | 769.11 | 898.02 | +1.31 | STX ahead |
| 2026-09-09 | 790.15 | 939.62 | +1.13 | STX ahead |
| 2026-09-08 | 806.62 | 929.91 | +1.41 | STX ahead |
| 2026-09-04 | 757.47 | 910.74 | +1.00 | STX ahead |
| 2026-09-03 | 712.28 | 860.30 | +0.95 | STX ahead |
| 2026-09-02 | 721.14 | 874.58 | +0.90 | STX ahead |
| 2026-09-01 | 728.36 | 877.58 | +0.95 | STX ahead |
| 2026-08-31 | 738.83 | 877.80 | +1.06 | STX ahead |
| 2026-08-28 | 740.06 | 895.14 | +0.89 | STX ahead |
| 2026-08-27 | 755.62 | 900.10 | +1.01 | STX ahead |
| 2026-08-26 | 754.88 | 913.51 | +0.86 | STX ahead |
| 2026-08-25 | 732.85 | 878.19 | +0.94 | STX ahead |
| 2026-08-24 | 708.75 | 848.24 | +0.94 | STX ahead |
| 2026-08-21 | 758.12 | 895.12 | +1.05 | STX ahead |
| 2026-08-20 | 758.33 | 913.84 | +0.86 | STX ahead |
| 2026-08-19 | 742.56 | 900.28 | +0.79 | STX ahead |
| 2026-08-18 | 805.99 | 966.66 | +0.88 | STX ahead |
| 2026-08-17 | 887.25 | 1044.30 | +1.03 | STX ahead |
| 2026-08-14 | 868.21 | 991.28 | +1.28 | STX ahead |
| 2026-08-13 | 821.77 | 949.38 | +1.17 | STX ahead |
| 2026-08-12 | 783.28 | 884.71 | +1.36 | STX ahead |
| 2026-08-11 | 731.82 | 853.21 | +1.09 | STX ahead |
| 2026-08-10 | 714.40 | 854.01 | +0.87 | STX ahead |
| 2026-08-07 | 724.90 | 846.14 | +1.06 | STX ahead |
| 2026-08-06 | 760.75 | 879.69 | +1.14 | STX ahead |
| 2026-08-05 | 747.11 | 1011.49 | -0.18 | near the usual relationship |
| 2026-08-04 | 753.97 | 1068.75 | -0.57 | WDC ahead |
| 2026-08-03 | 741.22 | 1027.17 | -0.39 | near the usual relationship |
| 2026-07-31 | 763.58 | 1061.50 | -0.42 | near the usual relationship |
| 2026-07-30 | 759.61 | 1038.51 | -0.29 | near the usual relationship |
| 2026-07-29 | 681.80 | 900.18 | -0.02 | near the usual relationship |
| 2026-07-28 | 666.52 | 903.05 | -0.23 | near the usual relationship |
| 2026-07-27 | 728.67 | 970.09 | -0.10 | near the usual relationship |
| 2026-07-24 | 759.62 | 1012.71 | -0.12 | near the usual relationship |
| 2026-07-23 | 814.63 | 1087.72 | -0.14 | near the usual relationship |
| 2026-07-22 | 809.94 | 1084.55 | -0.17 | near the usual relationship |
| 2026-07-21 | 795.42 | 1068.42 | -0.20 | near the usual relationship |
| 2026-07-20 | 715.71 | 949.63 | -0.11 | near the usual relationship |
| 2026-07-17 | 702.52 | 929.76 | -0.10 | near the usual relationship |
| 2026-07-16 | 664.90 | 909.48 | -0.35 | near the usual relationship |
| 2026-07-15 | 738.76 | 1001.10 | -0.29 | near the usual relationship |
| 2026-07-14 | 783.37 | 1097.50 | -0.54 | WDC ahead |
| 2026-07-13 | 767.62 | 1082.37 | -0.60 | WDC ahead |
| 2026-07-10 | 811.93 | 1135.04 | -0.54 | WDC ahead |
| 2026-07-09 | 793.87 | 1126.20 | -0.65 | WDC ahead |
| 2026-07-08 | 767.05 | 1072.14 | -0.55 | WDC ahead |
| 2026-07-07 | 738.17 | 1036.68 | -0.59 | WDC ahead |
| 2026-07-06 | 774.40 | 1125.05 | -0.83 | WDC ahead |
| 2026-07-02 | 731.50 | 1050.12 | -0.76 | WDC ahead |
| 2026-07-01 | 816.26 | 1165.79 | -0.73 | WDC ahead |
| 2026-06-30 | 860.68 | 1244.40 | -0.82 | WDC ahead |
| 2026-06-29 | 863.83 | 1270.04 | -0.94 | WDC ahead |
| 2026-06-26 | 802.62 | 1142.57 | -0.72 | WDC ahead |
| 2026-06-25 | 914.52 | 1315.85 | -0.80 | WDC ahead |
| 2026-06-24 | 885.88 | 1254.36 | -0.70 | WDC ahead |
| 2026-06-23 | 926.32 | 1306.81 | -0.68 | WDC ahead |
| 2026-06-22 | 975.78 | 1427.35 | -0.93 | WDC ahead |
| 2026-06-18 | 954.54 | 1453.86 | -1.21 | WDC ahead |
| 2026-06-17 | 950.83 | 1387.43 | -0.93 | WDC ahead |
| 2026-06-16 | 919.85 | 1326.93 | -0.86 | WDC ahead |
| 2026-06-15 | 908.67 | 1273.26 | -0.68 | WDC ahead |
| 2026-06-12 | 830.40 | 1096.73 | -0.30 | near the usual relationship |
| 2026-06-11 | 774.25 | 1031.20 | -0.36 | near the usual relationship |
| 2026-06-10 | 727.78 | 954.83 | -0.27 | near the usual relationship |
| 2026-06-09 | 754.56 | 1008.66 | -0.39 | near the usual relationship |
| 2026-06-08 | 781.99 | 1026.61 | -0.29 | near the usual relationship |
| 2026-06-05 | 755.86 | 996.97 | -0.32 | near the usual relationship |
| 2026-06-04 | 825.89 | 1121.23 | -0.51 | WDC ahead |
| 2026-06-03 | 839.00 | 1157.49 | -0.61 | WDC ahead |
| 2026-06-02 | 826.44 | 1097.07 | -0.38 | near the usual relationship |
| 2026-06-01 | 821.67 | 1064.15 | -0.24 | near the usual relationship |
| 2026-05-29 | 784.69 | 1034.94 | -0.35 | near the usual relationship |
| 2026-05-28 | 785.52 | 1034.89 | -0.35 | near the usual relationship |
| 2026-05-27 | 776.54 | 1033.76 | -0.42 | near the usual relationship |
| 2026-05-26 | 754.33 | 1022.16 | -0.54 | WDC ahead |
| 2026-05-22 | 724.88 | 943.51 | -0.30 | near the usual relationship |
| 2026-05-21 | 722.85 | 947.76 | -0.35 | near the usual relationship |
| 2026-05-20 | 669.88 | 895.47 | -0.47 | near the usual relationship |
| 2026-05-19 | 654.08 | 888.02 | -0.57 | WDC ahead |
| 2026-05-18 | 660.76 | 893.64 | -0.55 | WDC ahead |
| 2026-05-15 | 709.48 | 939.11 | -0.43 | near the usual relationship |
| 2026-05-14 | 717.77 | 953.00 | -0.45 | near the usual relationship |
| 2026-05-13 | 729.00 | 962.62 | -0.42 | near the usual relationship |
| 2026-05-12 | 721.37 | 952.20 | -0.43 | near the usual relationship |
| 2026-05-11 | 743.85 | 1004.98 | -0.57 | WDC ahead |
| 2026-05-08 | 698.04 | 935.17 | -0.52 | WDC ahead |
| 2026-05-07 | 683.59 | 903.83 | -0.45 | near the usual relationship |
| 2026-05-06 | 701.41 | 941.31 | -0.54 | WDC ahead |
| 2026-05-05 | 687.67 | 906.46 | -0.44 | near the usual relationship |
| 2026-05-04 | 658.70 | 861.84 | -0.40 | near the usual relationship |
| 2026-05-01 | 648.35 | 840.72 | -0.36 | near the usual relationship |
| 2026-04-30 | 600.82 | 846.57 | -0.85 | WDC ahead |
| 2026-04-29 | 573.76 | 804.17 | -0.82 | WDC ahead |
| 2026-04-28 | 516.44 | 761.76 | -1.13 | WDC ahead |
| 2026-04-27 | 531.45 | 780.73 | -1.12 | WDC ahead |
| 2026-04-24 | 522.88 | 787.10 | -1.27 | WDC ahead |
| 2026-04-23 | 524.10 | 785.39 | -1.26 | WDC ahead |
| 2026-04-22 | 517.20 | 758.07 | -1.13 | WDC ahead |
| 2026-04-21 | 499.38 | 747.77 | -1.27 | WDC ahead |
| 2026-04-20 | 481.40 | 728.87 | -1.35 | WDC ahead |
| 2026-04-17 | 488.54 | 725.77 | -1.25 | WDC ahead |
| 2026-04-16 | 474.32 | 704.67 | -1.26 | WDC ahead |
| 2026-04-15 | 463.43 | 711.12 | -1.46 | WDC ahead |
| 2026-04-14 | 475.78 | 713.50 | -1.34 | WDC ahead |
| 2026-04-13 | 457.80 | 682.21 | -1.31 | WDC ahead |
| 2026-04-10 | 448.74 | 669.10 | -1.33 | WDC ahead |
| 2026-04-09 | 446.64 | 658.28 | -1.27 | WDC ahead |
| 2026-04-08 | 442.65 | 660.04 | -1.35 | WDC ahead |
| 2026-04-07 | 418.05 | 607.78 | -1.20 | WDC ahead |
| 2026-04-06 | 404.30 | 592.57 | -1.26 | WDC ahead |
| 2026-04-02 | 382.95 | 574.68 | -1.42 | WDC ahead |
| 2026-04-01 | 377.38 | 580.06 | -1.58 | WDC ahead |
| 2026-03-31 | 349.41 | 526.99 | -1.48 | WDC ahead |
| 2026-03-30 | 323.25 | 490.32 | -1.53 | WDC ahead |
| 2026-03-27 | 338.99 | 536.44 | -1.81 | WDC ahead |
| 2026-03-26 | 337.84 | 532.56 | -1.80 | WDC ahead |
| 2026-03-25 | 368.55 | 576.96 | -1.78 | WDC ahead |
| 2026-03-24 | 379.02 | 586.53 | -1.72 | WDC ahead |
| 2026-03-23 | 360.35 | 574.33 | -1.93 | WDC ahead |
| 2026-03-20 | 366.78 | 571.04 | -1.80 | WDC ahead |
| 2026-03-19 | 387.62 | 617.47 | -1.97 | WDC ahead |
| 2026-03-18 | 362.80 | 594.03 | -2.18 | WDC ahead |
| 2026-03-17 | 375.57 | 611.39 | -2.17 | WDC ahead |
| 2026-03-16 | 355.67 | 557.62 | -1.95 | WDC ahead |
| 2026-03-13 | 342.23 | 530.50 | -1.90 | WDC ahead |
| 2026-03-12 | 333.55 | 508.85 | -1.81 | WDC ahead |
| 2026-03-11 | 344.25 | 523.72 | -1.81 | WDC ahead |
| 2026-03-10 | 342.75 | 518.67 | -1.80 | WDC ahead |
| 2026-03-09 | 333.87 | 510.57 | -1.89 | WDC ahead |
| 2026-03-06 | 314.66 | 477.81 | -1.86 | WDC ahead |
| 2026-03-05 | 327.63 | 504.66 | -1.98 | WDC ahead |
| 2026-03-04 | 334.47 | 509.08 | -1.92 | WDC ahead |
| 2026-03-03 | 318.96 | 488.26 | -1.99 | WDC ahead |
| 2026-03-02 | 338.49 | 526.19 | -2.12 | WDC ahead |
| 2026-02-27 | 363.75 | 544.93 | -1.88 | WDC ahead |
| 2026-02-26 | 365.39 | 549.90 | -1.94 | WDC ahead |
| 2026-02-25 | 376.25 | 566.85 | -1.97 | WDC ahead |
| 2026-02-24 | 353.21 | 527.15 | -1.92 | WDC ahead |
| 2026-02-23 | 363.36 | 546.34 | -2.00 | WDC ahead |
| 2026-02-20 | 366.67 | 556.27 | -2.09 | WDC ahead |
| 2026-02-19 | 364.76 | 554.62 | -2.13 | WDC ahead |
| 2026-02-18 | 378.29 | 577.78 | -2.20 | WDC ahead |
| 2026-02-17 | 370.98 | 553.53 | -2.05 | WDC ahead |
| 2026-02-13 | 379.94 | 548.60 | -1.82 | WDC ahead |
| 2026-02-12 | 384.56 | 553.51 | -1.81 | WDC ahead |
| 2026-02-11 | 363.23 | 533.32 | -1.99 | WDC ahead |
| 2026-02-10 | 353.40 | 511.54 | -1.90 | WDC ahead |
| 2026-02-09 | 379.06 | 557.19 | -2.04 | WDC ahead |
| 2026-02-06 | 382.91 | 550.54 | -1.89 | WDC ahead |
| 2026-02-05 | 361.62 | 506.92 | -1.71 | WDC ahead |
| 2026-02-04 | 373.38 | 524.89 | -1.75 | WDC ahead |
| 2026-02-03 | 396.41 | 565.47 | -1.89 | WDC ahead |
| 2026-02-02 | 386.15 | 526.48 | -1.54 | WDC ahead |
| 2026-01-30 | 363.62 | 487.52 | -1.42 | WDC ahead |
| 2026-01-29 | 398.30 | 542.42 | -1.56 | WDC ahead |
| 2026-01-28 | 395.05 | 544.93 | -1.68 | WDC ahead |
| 2026-01-27 | 331.57 | 492.25 | -2.31 | WDC ahead |
| 2026-01-26 | 319.56 | 469.24 | -2.25 | WDC ahead |
| 2026-01-23 | 308.69 | 460.55 | -2.42 | WDC ahead |
| 2026-01-22 | 309.07 | 474.00 | -2.70 | WDC ahead |
| 2026-01-21 | 307.01 | 471.29 | -2.76 | WDC ahead |
| 2026-01-20 | 290.75 | 434.41 | -2.57 | WDC ahead |
| 2026-01-16 | 290.97 | 431.56 | -2.54 | WDC ahead |
| 2026-01-15 | 285.69 | 432.71 | -2.78 | WDC ahead |
| 2026-01-14 | 278.52 | 418.88 | -2.77 | WDC ahead |
| 2026-01-13 | 284.02 | 416.93 | -2.59 | WDC ahead |
| 2026-01-12 | 286.73 | 413.31 | -2.45 | WDC ahead |
| 2026-01-09 | 271.15 | 390.55 | -2.47 | WDC ahead |
| 2026-01-08 | 253.72 | 365.65 | -2.51 | WDC ahead |
| 2026-01-07 | 274.94 | 389.42 | -2.38 | WDC ahead |
| 2026-01-06 | 294.70 | 427.41 | -2.64 | WDC ahead |
| 2026-01-05 | 258.50 | 366.04 | -2.45 | WDC ahead |
| 2026-01-02 | 256.46 | 365.69 | -2.56 | WDC ahead |
| 2025-12-31 | 245.62 | 335.63 | -2.16 | WDC ahead |
| 2025-12-30 | 249.80 | 343.01 | -2.23 | WDC ahead |
| 2025-12-29 | 250.89 | 350.07 | -2.43 | WDC ahead |
| 2025-12-26 | 255.28 | 353.69 | -2.39 | WDC ahead |
| 2025-12-24 | 254.43 | 349.83 | -2.34 | WDC ahead |
| 2025-12-23 | 252.23 | 347.28 | -2.39 | WDC ahead |
| 2025-12-22 | 252.27 | 344.38 | -2.33 | WDC ahead |
| 2025-12-19 | 264.32 | 352.79 | -2.11 | WDC ahead |
| 2025-12-18 | 260.44 | 340.97 | -1.92 | WDC ahead |
| 2025-12-17 | 247.64 | 323.92 | -1.93 | WDC ahead |
| 2025-12-16 | 256.98 | 340.12 | -2.08 | WDC ahead |
| 2025-12-15 | 254.71 | 335.18 | -2.04 | WDC ahead |
| 2025-12-12 | 256.55 | 343.56 | -2.26 | WDC ahead |
| 2025-12-11 | 274.57 | 364.72 | -2.19 | WDC ahead |
| 2025-12-10 | 266.61 | 354.49 | -2.22 | WDC ahead |
| 2025-12-09 | 252.28 | 330.31 | -2.06 | WDC ahead |
| 2025-12-08 | 254.56 | 330.78 | -1.98 | WDC ahead |
| 2025-12-05 | 248.65 | 329.04 | -2.21 | WDC ahead |
| 2025-12-04 | 236.92 | 313.67 | -2.23 | WDC ahead |
| 2025-12-03 | 230.71 | 303.13 | -2.16 | WDC ahead |
| 2025-12-02 | 238.02 | 311.70 | -2.14 | WDC ahead |
| 2025-12-01 | 240.90 | 318.62 | -2.28 | WDC ahead |
| 2025-11-28 | 246.78 | 318.21 | -2.00 | WDC ahead |
| 2025-11-26 | 242.85 | 307.32 | -1.79 | WDC ahead |
| 2025-11-25 | 233.58 | 302.78 | -2.11 | WDC ahead |
| 2025-11-24 | 225.99 | 294.05 | -2.18 | WDC ahead |
| 2025-11-21 | 211.82 | 271.18 | -2.01 | WDC ahead |
| 2025-11-20 | 214.50 | 273.21 | -1.97 | WDC ahead |
| 2025-11-19 | 231.12 | 299.98 | -2.23 | WDC ahead |
| 2025-11-18 | 226.42 | 297.81 | -2.44 | WDC ahead |
| 2025-11-17 | 233.13 | 316.50 | -2.90 | WDC ahead |
| 2025-11-14 | 230.30 | 307.50 | -2.73 | WDC ahead |
| 2025-11-13 | 234.18 | 306.19 | -2.50 | WDC ahead |
| 2025-11-12 | 252.64 | 323.63 | -2.25 | WDC ahead |
| 2025-11-11 | 256.87 | 331.19 | -2.37 | WDC ahead |
| 2025-11-10 | 262.21 | 339.43 | -2.46 | WDC ahead |
| 2025-11-07 | 249.15 | 317.48 | -2.28 | WDC ahead |
| 2025-11-06 | 248.37 | 318.74 | -2.41 | WDC ahead |
| 2025-11-05 | 245.96 | 311.92 | -2.27 | WDC ahead |
| 2025-11-04 | 223.31 | 296.49 | -2.98 | WDC ahead |
| 2025-11-03 | 236.84 | 307.87 | -2.73 | WDC ahead |
| 2025-10-31 | 228.22 | 292.65 | -2.57 | WDC ahead |
| 2025-10-30 | 239.33 | 269.12 | -0.63 | WDC ahead |
| 2025-10-29 | 236.91 | 275.45 | -1.12 | WDC ahead |
| 2025-10-28 | 198.89 | 243.38 | -1.90 | WDC ahead |
| 2025-10-27 | 205.42 | 246.79 | -1.64 | WDC ahead |
| 2025-10-24 | 208.81 | 252.17 | -1.74 | WDC ahead |
| 2025-10-23 | 201.94 | 244.94 | -1.82 | WDC ahead |
| 2025-10-22 | 191.80 | 234.71 | -1.98 | WDC ahead |
| 2025-10-21 | 191.38 | 236.54 | -2.16 | WDC ahead |
| 2025-10-20 | 191.22 | 236.77 | -2.21 | WDC ahead |
| 2025-10-17 | 201.03 | 245.87 | -2.05 | WDC ahead |
| 2025-10-16 | 201.60 | 245.33 | -1.99 | WDC ahead |
| 2025-10-15 | 195.67 | 234.65 | -1.78 | WDC ahead |
| 2025-10-14 | 188.75 | 220.41 | -1.38 | WDC ahead |
| 2025-10-13 | 195.78 | 231.57 | -1.59 | WDC ahead |
| 2025-10-10 | 191.21 | 224.87 | -1.52 | WDC ahead |
| 2025-10-09 | 197.73 | 233.21 | -1.58 | WDC ahead |
| 2025-10-08 | 200.10 | 236.09 | -1.60 | WDC ahead |
| 2025-10-07 | 200.69 | 233.66 | -1.40 | WDC ahead |
| 2025-10-06 | 216.58 | 244.08 | -0.89 | WDC ahead |
| 2025-10-03 | 225.46 | 255.83 | -1.01 | WDC ahead |
| 2025-10-02 | 227.20 | 255.73 | -0.88 | WDC ahead |
| 2025-10-01 | 229.08 | 254.43 | -0.67 | WDC ahead |
| 2025-09-30 | 210.54 | 233.91 | -0.68 | WDC ahead |
| 2025-09-29 | 204.37 | 227.44 | -0.71 | WDC ahead |
| 2025-09-26 | 194.00 | 208.23 | -0.14 | near the usual relationship |
| 2025-09-25 | 196.08 | 208.87 | -0.02 | near the usual relationship |
| 2025-09-24 | 199.52 | 213.71 | -0.10 | near the usual relationship |
| 2025-09-23 | 203.47 | 214.80 | +0.13 | near the usual relationship |
| 2025-09-22 | 204.54 | 219.01 | -0.10 | near the usual relationship |
| 2025-09-19 | 197.32 | 207.74 | +0.17 | near the usual relationship |
| 2025-09-18 | 193.22 | 204.86 | +0.06 | near the usual relationship |
| 2025-09-17 | 190.30 | 196.66 | +0.47 | near the usual relationship |
| 2025-09-16 | 188.31 | 200.85 | -0.03 | near the usual relationship |
| 2025-09-15 | 188.30 | 199.48 | +0.07 | near the usual relationship |
| 2025-09-12 | 174.80 | 190.27 | -0.36 | near the usual relationship |
| 2025-09-11 | 175.54 | 187.33 | -0.05 | near the usual relationship |
| 2025-09-10 | 172.17 | 185.13 | -0.17 | near the usual relationship |
| 2025-09-09 | 170.88 | 184.19 | -0.22 | near the usual relationship |
| 2025-09-08 | 168.78 | 181.75 | -0.20 | near the usual relationship |
| 2025-09-05 | 167.82 | 179.32 | -0.08 | near the usual relationship |
| 2025-09-04 | 164.09 | 176.30 | -0.16 | near the usual relationship |
| 2025-09-03 | 157.26 | 167.55 | -0.03 | near the usual relationship |
| 2025-09-02 | 152.07 | 159.58 | +0.21 | near the usual relationship |
| 2025-08-29 | 149.30 | 156.52 | +0.23 | near the usual relationship |
| 2025-08-28 | 153.75 | 159.84 | +0.36 | near the usual relationship |
| 2025-08-27 | 149.16 | 157.17 | +0.15 | near the usual relationship |
| 2025-08-26 | 147.38 | 155.30 | +0.14 | near the usual relationship |
| 2025-08-25 | 146.27 | 154.34 | +0.12 | near the usual relationship |
| 2025-08-22 | 142.00 | 149.96 | +0.11 | near the usual relationship |
| 2025-08-21 | 137.89 | 145.46 | +0.12 | near the usual relationship |
| 2025-08-20 | 141.28 | 147.37 | +0.30 | near the usual relationship |
| 2025-08-19 | 140.86 | 147.80 | +0.21 | near the usual relationship |
| 2025-08-18 | 141.54 | 148.63 | +0.20 | near the usual relationship |
| 2025-08-15 | 137.74 | 146.24 | +0.02 | near the usual relationship |
| 2025-08-14 | 138.90 | 148.54 | -0.09 | near the usual relationship |
| 2025-08-13 | 139.96 | 148.21 | +0.06 | near the usual relationship |
| 2025-08-12 | 138.77 | 147.89 | -0.04 | near the usual relationship |
| 2025-08-11 | 135.29 | 145.42 | -0.18 | near the usual relationship |
| 2025-08-08 | 134.19 | 146.06 | -0.38 | near the usual relationship |
| 2025-08-07 | 132.09 | 145.03 | -0.53 | WDC ahead |
| 2025-08-06 | 131.35 | 143.74 | -0.48 | near the usual relationship |
| 2025-08-05 | 135.34 | 147.76 | -0.44 | near the usual relationship |
| 2025-08-04 | 138.08 | 150.58 | -0.43 | near the usual relationship |
| 2025-08-01 | 138.08 | 149.14 | -0.28 | near the usual relationship |
| 2025-07-31 | 140.04 | 153.31 | -0.49 | near the usual relationship |
| 2025-07-30 | 131.48 | 139.17 | +0.05 | near the usual relationship |
| 2025-07-29 | 136.18 | 137.57 | +0.79 | STX ahead |
| 2025-07-28 | 134.20 | 134.40 | +0.94 | STX ahead |
| 2025-07-25 | 134.58 | 134.08 | +1.03 | STX ahead |
| 2025-07-24 | 136.22 | 134.47 | +1.18 | STX ahead |
| 2025-07-23 | 136.25 | 135.05 | +1.13 | STX ahead |
| 2025-07-22 | 130.74 | 130.65 | +1.01 | STX ahead |
| 2025-07-21 | 133.46 | 133.92 | +0.95 | STX ahead |
| 2025-07-18 | 132.96 | 132.48 | +1.07 | STX ahead |
| 2025-07-17 | 130.86 | 130.57 | +1.05 | STX ahead |
| 2025-07-16 | 131.22 | 129.62 | +1.21 | STX ahead |
| 2025-07-15 | 132.94 | 131.57 | +1.19 | STX ahead |
| 2025-07-14 | 132.96 | 130.40 | +1.34 | STX ahead |
| 2025-07-11 | 131.27 | 128.86 | +1.32 | STX ahead |
| 2025-07-10 | 128.88 | 126.75 | +1.30 | STX ahead |
| 2025-07-09 | 126.66 | 125.94 | +1.14 | STX ahead |
| 2025-07-08 | 128.85 | 124.73 | +1.54 | STX ahead |
| 2025-07-07 | 132.35 | 127.06 | +1.67 | STX ahead |
| 2025-07-03 | 133.29 | 128.74 | +1.59 | STX ahead |
| 2025-07-02 | 135.52 | 128.16 | +1.91 | STX ahead |
| 2025-07-01 | 129.36 | 124.38 | +1.68 | STX ahead |
| 2025-06-30 | 128.73 | 124.67 | +1.58 | STX ahead |
| 2025-06-27 | 126.15 | 123.31 | +1.46 | STX ahead |
| 2025-06-26 | 125.48 | 123.74 | +1.34 | STX ahead |
| 2025-06-25 | 123.56 | 121.86 | +1.34 | STX ahead |
| 2025-06-24 | 121.58 | 120.93 | +1.23 | STX ahead |
| 2025-06-23 | 118.69 | 117.64 | +1.29 | STX ahead |
| 2025-06-20 | 116.80 | 115.51 | +1.32 | STX ahead |
| 2025-06-18 | 117.11 | 115.32 | +1.39 | STX ahead |
| 2025-06-17 | 116.72 | 114.11 | +1.50 | STX ahead |
| 2025-06-16 | 116.87 | 111.85 | +1.81 | STX ahead |
| 2025-06-13 | 113.51 | 108.52 | +1.83 | STX ahead |
| 2025-06-12 | 112.44 | 108.67 | +1.69 | STX ahead |
| 2025-06-11 | 112.82 | 108.46 | +1.77 | STX ahead |
| 2025-06-10 | 114.15 | 109.01 | +1.87 | STX ahead |
| 2025-06-09 | 116.10 | 111.09 | +1.84 | STX ahead |
| 2025-06-06 | 113.24 | 108.03 | +1.89 | STX ahead |
| 2025-06-05 | 113.90 | 107.25 | +2.06 | STX ahead |
| 2025-06-04 | 113.84 | 106.04 | +2.22 | STX ahead |
| 2025-06-03 | 109.91 | 104.76 | +1.92 | STX ahead |
| 2025-06-02 | 106.27 | 101.68 | +1.87 | STX ahead |
| 2025-05-30 | 105.19 | 100.43 | +1.91 | STX ahead |
| 2025-05-29 | 105.37 | 102.38 | +1.68 | STX ahead |
| 2025-05-28 | 104.66 | 101.99 | +1.65 | STX ahead |
| 2025-05-27 | 104.40 | 100.96 | +1.76 | STX ahead |
| 2025-05-23 | 100.55 | 97.76 | +1.70 | STX ahead |
| 2025-05-22 | 97.09 | 97.10 | +1.35 | STX ahead |
| 2025-05-21 | 93.14 | 96.42 | +0.91 | STX ahead |
| 2025-05-20 | 95.41 | 98.64 | +0.94 | STX ahead |
| 2025-05-19 | 97.25 | 98.82 | +1.16 | STX ahead |
| 2025-05-16 | 96.14 | 97.39 | +1.21 | STX ahead |
| 2025-05-15 | 95.82 | 96.93 | +1.24 | STX ahead |
| 2025-05-14 | 93.82 | 95.86 | +1.12 | STX ahead |
| 2025-05-13 | 94.07 | 95.49 | +1.21 | STX ahead |
| 2025-05-12 | 90.93 | 90.73 | +1.43 | STX ahead |
| 2025-05-09 | 85.36 | 85.92 | +1.33 | STX ahead |
| 2025-05-08 | 85.89 | 86.31 | +1.35 | STX ahead |
| 2025-05-07 | 85.13 | 86.31 | +1.25 | STX ahead |
| 2025-05-06 | 83.75 | 86.29 | +1.06 | STX ahead |
| 2025-05-05 | 83.46 | 87.73 | +0.82 | STX ahead |
| 2025-05-02 | 83.01 | 87.07 | +0.85 | STX ahead |
| 2025-05-01 | 80.28 | 85.63 | +0.66 | STX ahead |
| 2025-04-30 | 81.19 | 85.45 | +0.82 | STX ahead |
| 2025-04-29 | 72.78 | 79.14 | +0.45 | near the usual relationship |
| 2025-04-28 | 73.28 | 79.70 | +0.45 | near the usual relationship |
| 2025-04-25 | 73.76 | 79.45 | +0.57 | STX ahead |
| 2025-04-24 | 74.06 | 78.26 | +0.79 | STX ahead |
| 2025-04-23 | 69.65 | 73.45 | +0.82 | STX ahead |
| 2025-04-22 | 67.21 | 71.46 | +0.73 | STX ahead |
| 2025-04-21 | 65.94 | 70.06 | +0.74 | STX ahead |
| 2025-04-17 | 67.59 | 71.13 | +0.85 | STX ahead |
| 2025-04-16 | 64.95 | 69.40 | +0.69 | STX ahead |
| 2025-04-15 | 64.22 | 70.00 | +0.48 | near the usual relationship |
| 2025-04-14 | 64.81 | 69.79 | +0.62 | STX ahead |
| 2025-04-11 | 62.57 | 67.02 | +0.68 | STX ahead |
| 2025-04-10 | 62.20 | 67.94 | +0.48 | near the usual relationship |
| 2025-04-09 | 66.26 | 70.72 | +0.73 | STX ahead |
| 2025-04-08 | 59.35 | 61.47 | +1.05 | STX ahead |
| 2025-04-07 | 61.24 | 60.71 | +1.52 | STX ahead |
| 2025-04-04 | 59.52 | 59.50 | +1.44 | STX ahead |
| 2025-04-03 | 63.80 | 66.53 | +1.01 | STX ahead |
| 2025-04-02 | 76.28 | 81.40 | +0.78 | STX ahead |
| 2025-04-01 | 75.40 | 79.67 | +0.89 | STX ahead |
| 2025-03-31 | 75.77 | 78.77 | +1.07 | STX ahead |
| 2025-03-28 | 75.74 | 79.14 | +1.02 | STX ahead |
| 2025-03-27 | 78.04 | 81.65 | +1.01 | STX ahead |
| 2025-03-26 | 78.16 | 83.04 | +0.86 | STX ahead |
| 2025-03-25 | 78.45 | 84.54 | +0.72 | STX ahead |
| 2025-03-24 | 79.19 | 86.33 | +0.60 | STX ahead |
| 2025-03-21 | 78.73 | 85.06 | +0.70 | STX ahead |
| 2025-03-20 | 78.83 | 86.72 | +0.51 | STX ahead |
| 2025-03-19 | 79.32 | 87.48 | +0.49 | near the usual relationship |
| 2025-03-18 | 79.06 | 86.39 | +0.59 | STX ahead |
| 2025-03-17 | 80.73 | 87.19 | +0.71 | STX ahead |
| 2025-03-14 | 78.40 | 86.76 | +0.46 | near the usual relationship |
| 2025-03-13 | 76.36 | 81.89 | +0.79 | STX ahead |
| 2025-03-12 | 77.35 | 83.70 | +0.70 | STX ahead |
| 2025-03-11 | 77.57 | 81.44 | +1.03 | STX ahead |
| 2025-03-10 | 77.07 | 78.98 | +1.29 | STX ahead |
| 2025-03-07 | 78.49 | 81.24 | +1.19 | STX ahead |
| 2025-03-06 | 77.27 | 80.76 | +1.09 | STX ahead |
| 2025-03-05 | 82.44 | 86.11 | +1.10 | STX ahead |
| 2025-03-04 | 83.91 | 86.95 | +1.19 | STX ahead |
| 2025-03-03 | 89.24 | 91.59 | +1.29 | STX ahead |
| 2025-02-28 | 90.89 | 95.33 | +1.06 | STX ahead |
| 2025-02-27 | 89.79 | 93.91 | +1.09 | STX ahead |
| 2025-02-26 | 89.43 | 97.73 | +0.62 | STX ahead |
| 2025-02-25 | 88.94 | 95.60 | +0.80 | STX ahead |
| 2025-02-24 | 89.26 | 95.50 | +0.85 | STX ahead |
| 2025-02-21 | 89.95 | 102.50 | +0.17 | near the usual relationship |
| 2025-02-20 | 91.54 | 106.36 | -0.04 | near the usual relationship |
| 2025-02-19 | 91.87 | 106.67 | -0.04 | near the usual relationship |
| 2025-02-18 | 91.96 | 107.46 | -0.11 | near the usual relationship |
| 2025-02-14 | 90.50 | 102.03 | +0.27 | near the usual relationship |
| 2025-02-13 | 90.51 | 100.79 | +0.40 | near the usual relationship |
| 2025-02-12 | 88.49 | 100.37 | +0.20 | near the usual relationship |
| 2025-02-11 | 87.25 | 102.82 | -0.21 | near the usual relationship |
| 2025-02-10 | 87.23 | 103.00 | -0.23 | near the usual relationship |
| 2025-02-07 | 85.76 | 96.17 | +0.31 | near the usual relationship |
| 2025-02-06 | 86.10 | 96.20 | +0.35 | near the usual relationship |
| 2025-02-05 | 85.11 | 96.55 | +0.19 | near the usual relationship |
| 2025-02-04 | 84.29 | 95.20 | +0.24 | near the usual relationship |
| 2025-02-03 | 83.37 | 96.11 | +0.02 | near the usual relationship |
| 2025-01-31 | 85.94 | 97.17 | +0.23 | near the usual relationship |
| 2025-01-30 | 87.66 | 98.14 | +0.33 | near the usual relationship |
| 2025-01-29 | 88.64 | 93.69 | +0.94 | STX ahead |
| 2025-01-28 | 89.43 | 93.79 | +1.02 | STX ahead |
| 2025-01-27 | 92.29 | 96.08 | +1.10 | STX ahead |
| 2025-01-24 | 96.49 | 100.57 | +1.09 | STX ahead |
| 2025-01-23 | 96.70 | 102.46 | +0.92 | STX ahead |
| 2025-01-22 | 96.49 | 102.39 | +0.91 | STX ahead |
| 2025-01-21 | 90.31 | 100.60 | +0.39 | near the usual relationship |
| 2025-01-17 | 87.11 | 97.03 | +0.39 | near the usual relationship |
| 2025-01-16 | 84.79 | 95.85 | +0.23 | near the usual relationship |
| 2025-01-15 | 84.14 | 96.42 | +0.08 | near the usual relationship |
| 2025-01-14 | 81.37 | 93.60 | +0.03 | near the usual relationship |
| 2025-01-13 | 79.32 | 92.53 | -0.12 | near the usual relationship |
| 2025-01-10 | 79.26 | 93.72 | -0.26 | near the usual relationship |
| 2025-01-08 | 79.10 | 95.57 | -0.49 | near the usual relationship |
| 2025-01-07 | 79.91 | 96.78 | -0.52 | WDC ahead |
| 2025-01-06 | 79.48 | 97.94 | -0.71 | WDC ahead |
| 2025-01-03 | 79.51 | 95.58 | -0.46 | near the usual relationship |
| 2025-01-02 | 77.05 | 92.30 | -0.43 | near the usual relationship |
| 2024-12-31 | 76.98 | 88.96 | -0.06 | near the usual relationship |
| 2024-12-30 | 77.18 | 88.95 | -0.04 | near the usual relationship |
| 2024-12-27 | 77.94 | 90.56 | -0.13 | near the usual relationship |
| 2024-12-26 | 78.84 | 92.06 | -0.18 | near the usual relationship |
| 2024-12-24 | 78.92 | 92.05 | -0.17 | near the usual relationship |
| 2024-12-23 | 78.96 | 91.84 | -0.15 | near the usual relationship |
| 2024-12-20 | 77.87 | 89.87 | -0.08 | near the usual relationship |
| 2024-12-19 | 78.08 | 88.95 | +0.05 | near the usual relationship |
| 2024-12-18 | 81.70 | 94.79 | -0.14 | near the usual relationship |
| 2024-12-17 | 84.28 | 96.43 | -0.01 | near the usual relationship |
| 2024-12-16 | 85.25 | 97.42 | +0.00 | near the usual relationship |
| 2024-12-13 | 85.40 | 97.15 | +0.04 | near the usual relationship |
| 2024-12-12 | 87.09 | 98.45 | +0.10 | near the usual relationship |
| 2024-12-11 | 87.75 | 104.28 | -0.40 | near the usual relationship |
| 2024-12-10 | 87.04 | 102.67 | -0.33 | near the usual relationship |
| 2024-12-09 | 88.27 | 105.53 | -0.47 | near the usual relationship |
| 2024-12-06 | 87.86 | 106.03 | -0.57 | WDC ahead |
| 2024-12-05 | 87.57 | 107.58 | -0.75 | WDC ahead |
| 2024-12-04 | 87.08 | 107.92 | -0.85 | WDC ahead |
| 2024-12-03 | 88.12 | 106.95 | -0.65 | WDC ahead |
| 2024-12-02 | 92.01 | 109.55 | -0.46 | near the usual relationship |
| 2024-11-29 | 90.38 | 108.89 | -0.59 | WDC ahead |
| 2024-11-27 | 89.19 | 106.67 | -0.52 | WDC ahead |
| 2024-11-26 | 90.67 | 108.94 | -0.57 | WDC ahead |
| 2024-11-25 | 90.40 | 103.57 | -0.11 | near the usual relationship |
| 2024-11-22 | 88.85 | 99.10 | +0.14 | near the usual relationship |
| 2024-11-21 | 89.12 | 98.28 | +0.25 | near the usual relationship |
| 2024-11-20 | 87.42 | 95.24 | +0.37 | near the usual relationship |
| 2024-11-19 | 87.23 | 97.40 | +0.12 | near the usual relationship |
| 2024-11-18 | 86.53 | 96.34 | +0.15 | near the usual relationship |
| 2024-11-15 | 86.33 | 93.69 | +0.39 | near the usual relationship |
| 2024-11-14 | 86.92 | 94.32 | +0.39 | near the usual relationship |
| 2024-11-13 | 87.65 | 93.58 | +0.54 | STX ahead |
| 2024-11-12 | 89.01 | 95.42 | +0.51 | STX ahead |
| 2024-11-11 | 90.83 | 100.52 | +0.20 | near the usual relationship |
| 2024-11-08 | 93.45 | 103.85 | +0.15 | near the usual relationship |
| 2024-11-07 | 93.75 | 105.09 | +0.07 | near the usual relationship |
| 2024-11-06 | 91.85 | 104.30 | -0.06 | near the usual relationship |
| 2024-11-05 | 90.66 | 99.70 | +0.24 | near the usual relationship |
| 2024-11-04 | 89.09 | 97.30 | +0.30 | near the usual relationship |
| 2024-11-01 | 88.40 | 98.28 | +0.13 | near the usual relationship |
| 2024-10-31 | 89.52 | 97.43 | +0.32 | near the usual relationship |
| 2024-10-30 | 89.00 | 99.98 | +0.02 | near the usual relationship |
| 2024-10-29 | 90.38 | 101.89 | -0.02 | near the usual relationship |
| 2024-10-28 | 90.37 | 104.00 | -0.21 | near the usual relationship |
| 2024-10-25 | 91.87 | 103.61 | -0.03 | near the usual relationship |
| 2024-10-24 | 92.74 | 98.94 | +0.49 | near the usual relationship |
| 2024-10-23 | 92.33 | 99.37 | +0.40 | near the usual relationship |
| 2024-10-22 | 100.46 | 101.09 | +1.03 | STX ahead |
| 2024-10-21 | 100.26 | 100.34 | +1.09 | STX ahead |
| 2024-10-18 | 100.00 | 100.00 | +1.10 | STX ahead |
One-day company-specific moves (4+ standard deviations, which block ideas for 10 sessions): Oct 31, 2025 (STX -4.6%, WDC +8.8%); May 1, 2026 (STX +7.9%, WDC -0.7%); Aug 6, 2026 (STX +1.8%, WDC -13.0%). Upcoming earnings: STX Oct 27, 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
STX and WDC at a glance
STX Seagate Technology Holdings PLC Ordinary Shares (Ireland)
- Listing
- Nasdaq · SEC CIK 1137789
- Industry
- Electronic Components · SIC 3572 Computer Storage Devices
- Market value
- $151.1B
- Price history
- 2,521 daily closes, Oct 12, 2016 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.
Related
All pairs →Other rivals of STX and WDC
| Pair | Status | Ahead now | Industry |
|---|---|---|---|
| SNDK / WDC | Watchlist | SNDK by 1.11 sd | SIC 3572 Computer Storage Devices |
| SNDK / STX | Watchlist | SNDK by 0.85 sd | Electronic Components |
Follow the research behind the paper book
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Explore the private betaPaper 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.
