Market index
Philadelphia Semiconductor Index
The Philadelphia Semiconductor Index of leading US-listed chip companies. Spanning memory, foundry, and equipment, it is a standard overnight reference for the direction of Samsung Electronics and SK Hynix.
At a glance
Philadelphia Semiconductor Index: latest value and prior change
As of 2026-09-11, Philadelphia Semiconductor Index is 11,824 pt. It is 209.8 pt higher than 11,614 pt on 2026-09-10.
Across 141 available observations from 2026-02-20 to 2026-09-11, the latest value is at the tie-adjusted 59th percentile.
- Observed on
- Default comparison window
- 2026-02-20–2026-09-11
- Observations · observed cadence
- 141 · Daily
- Data source
- Naver Finance
A high or low percentile does not by itself make the indicator positive, negative, or a buy or sell signal.
Time-series chart
Philadelphia Semiconductor Index
2026-02-20–2026-09-11
Long-history series are stored as real provider observations. Index, FX, VIX, and ratio charts use historical backfill where providers expose it; Korean investor flow and margin-credit feeds expand as stable historical endpoints become available.
Recent observations and calculated changes
The ten latest chart observations. Change subtracts the previous observation; intervals vary with holidays, release schedules and missing data. A difference in rates or ratios is not an investment return.
| Observed | Value | Previous date | Difference (current − previous) |
|---|---|---|---|
| 2026-09-11 | 11,824 pt | 2026-09-10 | 209.8 pt |
| 2026-09-10 | 11,614 pt | 2026-09-09 | -317.2 pt |
| 2026-09-09 | 11,931 pt | 2026-09-08 | 43.45 pt |
| 2026-09-08 | 11,888 pt | 2026-09-04 | 152.6 pt |
| 2026-09-04 | 11,735 pt | 2026-09-03 | 383.1 pt |
| 2026-09-03 | 11,352 pt | 2026-09-02 | 12.88 pt |
| 2026-09-02 | 11,339 pt | 2026-09-01 | 50.64 pt |
| 2026-09-01 | 11,289 pt | 2026-08-31 | -246.4 pt |
| 2026-08-31 | 11,535 pt | 2026-08-28 | 65.39 pt |
| 2026-08-28 | 11,470 pt | 2026-08-27 | -412.5 pt |
Source: Naver Finance
Interpretation guide
The SOX index: Korea's overnight compass for semiconductor stocks
The Philadelphia Semiconductor Index (SOX) tracks thirty leading US-listed chip companies, including Nvidia, AMD, and TSMC's ADR. With semiconductors dominating Korea's market, the SOX's overnight move is the most widely watched reference for how Samsung Electronics, SK Hynix, and often the whole KOSPI will open the next morning.
What the index contains
SOX spans the full value chain — design, foundry, equipment, and materials. It prices expectations for the industry cycle rather than any single company, and in theme-driven phases like AI capex it moves with several times the market's volatility.
- Strength in equipment names (Applied Materials, ASML's ADR) signals an expanding capex cycle.
- SOX outperforming the Nasdaq means chip-specific optimism, not just broad risk appetite.
- As a deeply cyclical sector, SOX also works as a leading signal for global manufacturing.
The link to the Korean market
Samsung Electronics and SK Hynix together account for roughly a quarter of KOSPI's capitalization, so the SOX's overnight move feeds directly into Korean opening prices. But memory-centric Korea and the logic-and-equipment-heavy SOX can run on different cycles.
- If Korean chip stocks fail to follow a SOX rally, look for memory-specific news such as output cuts or price talks.
- When SOX and the won are favorable on the same day, foreign net buying in chips becomes more likely.
- Overlay TapeFlow's semiconductor exports YoY to compare price expectations against actual shipments.
Uses and misreads
Mechanically buying Korean chip stocks after a SOX rally usually means paying for news already priced into the open. Trend and relative strength beat any single level.
- Repeated gap-up opens that fade intraday suggest the overnight catalyst is exhausting.
- Korean chip names holding firm through a SOX correction points to genuine memory-cycle strength.
- In earnings season, single reports like Nvidia or Micron can swing the whole index — track the calendar.