Korea Semiconductor Cycle Index: every cycle since 2000
Across 6,356 trading days from 2000-10-09 to 2026-07-27, computed with one formula throughout, the index recorded 22 overheated phases and 4 depressed phases. Every one of them is listed below. The index updates daily, and this table is recomputed with it.
Where the index sits now
The index closed at 69.8 on 2026-07-27, back below the overheated threshold. The phase that ran from 2025-09-05 to 2026-07-23 — 213 trading days, the longest since 2000 — has still not fallen back to the neutral line of 50.
Overheated phases (75 and above)
| Period | Trading days | Peak | Days to neutral |
|---|---|---|---|
| 2001-12-28 – 2002-04-25 | 78 | 88.4 (2002-03-06) | 26 |
| 2003-07-07 – 2003-09-19 | 50 | 89.1 (2003-09-02) | 160 |
| 2003-10-16 – 2003-11-13 | 21 | 86.4 (2003-11-03) | 122 |
| 2004-01-07 – 2004-04-27 | 74 | 86.9 (2004-01-28) | 13 |
| 2005-07-07 – 2005-10-12 | 67 | 86.4 (2005-08-02) | 163 |
| 2005-11-11 – 2006-02-14 | 66 | 88.4 (2006-01-10) | 76 |
| 2009-07-07 – 2009-10-20 | 75 | 92.6 (2009-09-22) | 203 |
| 2009-12-07 – 2010-01-25 | 33 | 85.1 (2010-01-06) | 137 |
| 2010-03-30 – 2010-04-26 | 20 | 80.6 (2010-04-05) | 74 |
| 2011-01-13 – 2011-02-21 | 25 | 80.1 (2011-01-28) | 75 |
| 2011-04-05 – 2011-05-02 | 20 | 78.5 (2011-04-21) | 26 |
| 2016-08-19 – 2016-10-10 | 33 | 80.9 (2016-10-06) | 419 |
| 2016-11-22 – 2017-04-05 | 93 | 83.3 (2017-01-26) | 296 |
| 2017-04-25 – 2017-08-02 | 67 | 83.7 (2017-07-20) | 216 |
| 2017-09-11 – 2017-11-24 | 48 | 84.3 (2017-10-11) | 142 |
| 2019-12-16 – 2020-02-21 | 45 | 81.6 (2020-01-22) | 13 |
| 2020-11-13 – 2021-04-20 | 107 | 94.4 (2021-01-08) | 80 |
| 2023-05-26 – 2023-08-01 | 46 | 82.8 (2023-06-13) | 247 |
| 2024-03-04 – 2024-04-15 | 30 | 82.7 (2024-04-02) | 76 |
| 2024-06-13 – 2024-07-17 | 25 | 86.9 (2024-07-10) | 13 |
| 2025-06-25 – 2025-08-14 | 37 | 79.9 (2025-08-13) | Not yet |
| 2025-09-05 – Ongoing | 213 | 95.5 (2026-04-23) | Ongoing |
Depressed phases (25 and below)
| Period | Trading days | Trough | Days to neutral |
|---|---|---|---|
| 2000-10-09 – 2000-12-26 | 56 | 12.3 (2000-10-17) | 94 |
| 2001-02-28 – 2001-04-11 | 29 | 16.2 (2001-04-04) | 27 |
| 2003-01-24 – 2003-04-28 | 66 | 16.1 (2003-03-11) | 32 |
| 2008-10-06 – 2009-03-11 | 108 | 4.5 (2008-11-14) | 18 |
What the record shows
- The highest reading on record is 95.5 (2026-04-23); the lowest is 4.5 (2008-11-14).
- The longest overheated phase ran from 2025-09-05 to 2026-07-23, a span of 213 trading days.
- After an overheated phase ended, the index took a median of 101 trading days to fall back below the neutral line of 50. The spread is wide: one phase resolved in 13 days, another took 419.
- The most recent depressed phase ended on 2009-03-11. The index has not returned to that band in roughly 17 years since.
- This table records where the index has been. It does not forecast where it goes next: past readings in the same band were followed both by continued advances and by sharp reversals.
How the phases are defined
Consecutive days at or above 75 are grouped into an overheated phase; days at or below 25 form a depressed phase.
Ending a phase every time the index brushes the line for a day or two would split a single episode into fragments. Gaps of up to 10 trading days are therefore bridged, and phases shorter than 15 trading days are excluded.
"Days to neutral" counts trading days from the end of a phase until the index first closed below 50.
Download the full history (kss.json) · 2000-10-09 ~ 2026-07-27 · CC BY 4.0