Upcoming Hang Seng additions
Every change is announced days before it takes effect, and funds tracking the indexes must own the stock by the effective close. This page tracks that window: who is coming in, when, and how the stock is trading while the clock runs down.
Countdown to the effective close
No pending additions as of Sep 16, 2026
The index committee hasn't announced a change that is still waiting to take effect. New announcements show up here automatically with a live countdown — the most recent completed additions are below in the meantime.
Most recent additions
See what inclusion is worth →What usually happens after the bell
Measured from the effective-date close across 5 tracked Hang Seng additions.
| Window | Average | Median | Positive | vs Hang Seng |
|---|---|---|---|---|
| 1W | +9.5% | +9.5% | 100% | +9.5% |
| 1M | -4.9% | -4.9% | 0% | -4.9% |
| 3M | +17.1% | +17.1% | 100% | +17.1% |
| 6M | +13.0% | +13.0% | 100% | +13.0% |
| 1Y | +73.5% | +73.5% | 100% | +73.5% |
How Hang Seng additions work
Hang Seng Indexes reviews quarterly, announcing results in February, May, August and November. Changes take effect on the Monday following the first Friday of March, June, September and December. A change is announced first and only takes effect after the close on the effective date. Between those two dates, every fund tracking the index (2800.HK, EWH) has to buy the incoming stock, which is why the window matters to traders.
Across the 5 Hang Seng additions tracked here, the median notice between the announcement and the effective close is 24 days.
What happens to a stock after it joins Hang Seng
Inclusion is often described as a guaranteed pop. The tracked history is more mixed: the average stock ran up -2.7% in the 30 days into the effective close, then returned +9.5% in the first week (100% of additions were positive), -4.9% after one month, and +73.5% after a year. Returns are measured from the effective close and can also be viewed against the index itself, so a rising market doesn't get counted as an inclusion effect.
Best one-year outcome in this set: 0285.HK (BYD Electronic) at +73.5%. Worst: 0285.HK (BYD Electronic) at +73.5%.
When are Hang Seng changes announced?
Quarterly review (Feb / May / Aug / Nov) Scheduled review, announcement and effective dates for the next twelve months are listed on the index review calendar. Ad hoc changes — a takeover, a bankruptcy, a fast-track promotion — are announced outside that schedule, usually with a few days' notice.
Most recent Hang Seng additions
- 0285.HK — BYD Electronic joined the Hang Seng on Sep 5, 2022, replacing Quarterly review.
- 9618.HK — JD.com joined the Hang Seng on Jun 7, 2021, replacing Quarterly review.
- 2269.HK — WuXi Biologics joined the Hang Seng on Sep 7, 2020, replacing Quarterly review.
- 1810.HK — Xiaomi joined the Hang Seng on Sep 7, 2020, replacing Quarterly review.
- 9988.HK — Alibaba Group joined the Hang Seng on Sep 7, 2020, replacing Quarterly review.