Schwab International Index Fund (SWISX) Seasonality
Recurring seasonal patterns for SWISX — the calendar windows where Schwab International Index Fund has historically tended to rise or fall, with the win rate (how often it repeated) and average return for each, based on the last 10 years of price history.
SWISX seasonality at a glance
Over the last 10 years, SWISX's strongest seasonal window has been Dec 20 – Dec 30: it ended higher in 10 of 10 years (100% win rate) with an average return of +1.06% across a 10-day hold. On the weak side, SWISX has historically declined between Jun 7 – Jun 17, falling in 9 of 10 years (average -2.04%).
In total, our analysis finds 460 recurring seasonal windows for Schwab International Index Fund — 363 bullish and 97 bearish. The next high-win-rate window, Sep 21 – Oct 11, opens in 56 days. These figures describe historical behaviour only — not a forecast.
SWISX's upcoming & recent seasonal patterns
Holding period:10-day20-day30-dayOrdered by season — windows opening soon first, plus a couple of recently completed high-performers. Holding-period colors help you compare durations at a glance.
| Status | Seasonal window | Hold | Avg return | Win rate | This year |
|---|---|---|---|---|---|
| Completedended 4d ago | Jul 3 – Jul 23 | 20d | +1.46% | 80% | +0.35% |
| Completedended 4d ago | Jun 23 – Jul 23 | 30d | +1.82% | 90% | +0.67% |
| Upcomingin 56d | Sep 21 – Oct 11 | 20d | -1.37% | 80% | — |
| Upcomingin 57d | Sep 22 – Oct 12 | 20d | -1.56% | 80% | — |
| Upcomingin 91d | Oct 26 – Nov 5 | 10d | +1.47% | 80% | — |
| Upcomingin 96d | Oct 31 – Nov 10 | 10d | +2.63% | 80% | — |
| Upcomingin 105d | Nov 9 – Dec 9 | 30d | +2.02% | 80% | — |
Win rate = how often the pattern repeated in the same direction. Average return = the mean move across all analysed years. Past performance does not guarantee future results.
Explore SWISX seasonality in full
See the seasonal curve chart, filter by win rate and return, and track upcoming windows — free during beta.
SWISX seasonality FAQ
What has historically been the best month to buy SWISX stock?
Based on the last 10 years of price data, SWISX's strongest seasonal window starts in December: Dec 20 to Dec 30, which ended higher in 10 of 10 years (100% win rate) with an average return of +1.06%. Past seasonal patterns do not guarantee future performance.
What is SWISX's strongest seasonal pattern?
SWISX's highest-win-rate pattern in our data is the Dec 20 – Dec 30 window (10-day hold): up in 10 of the last 10 years with an average move of +1.06%.
When has SWISX historically performed worst?
SWISX's weakest recurring window has been Jun 7 to Jun 17, declining in 9 of 10 years with an average return of -2.04%.
How reliable are SWISX's seasonal patterns?
Each SWISX pattern is scored by its historical win rate — the share of the last 10 years it repeated in the same direction. SWISX currently shows 460 recurring windows (363 bullish, 97 bearish). Seasonality describes historical tendencies only; it is not a prediction, and past performance does not guarantee future results.
What is SWISX stock seasonality?
Stock seasonality is the tendency of a stock to perform in a similar way during the same period each year. By analysing Schwab International Index Fund's price history across many years, SeasonalityX identifies recurring calendar windows — exact start and end dates — where SWISX has repeatedly risen (bullish) or fallen (bearish). Each pattern is scored by its win rate and average return so you can judge how reliable and how strong it has been.
Seasonality is one input among many — it works best alongside your own research and risk management. Learn more in our guide to seasonal analysis and the tutorials.