TOKYO, 16 September 2026 — Japan’s Nikkei 225 began Wednesday at 63,672.13, an opening gain of 188.03 points, or 0.30%, from Tuesday’s 63,484.10 close. The positive start did not hold through the first hour: Yahoo Finance’s delayed observation at 10:04:25 JST put the index at 63,463.60, down 20.50 points, or 0.03%, for the session.
Opening gap and subsequent trading
| 15 September closing level | 63,484.10 points |
|---|---|
| 16 September opening level, 09:00 JST | 63,672.13 points |
| Calculated opening gap | +188.03 points / +0.30% |
| Delayed reading, 10:04:25 JST | 63,463.60 points |
The opening and prior-close figures are confirmed by Nikkei’s own index service and its historical records. CapKet calculates the percentage gap using the previous close as the denominator; it is not the later intraday percentage change.
The reversal in context
By the quoted observation, the benchmark had lost 208.53 points from its opening value. That reversal was larger than the initial positive gap, leaving the index marginally below its prior close. It demonstrates why a higher opening alone cannot establish the direction of an entire trading day. The supplied data does not identify which individual shares contributed most to the reversal, so this report does not assign an unverified company or sector catalyst.
Nikkei 225 uses price weighting across 225 selected Tokyo Stock Exchange Prime Market stocks. Its performance is therefore not interchangeable with the broader, capitalization-weighted TOPIX. A movement in a high-priced constituent can have a different effect on the two gauges.
What comes next
Tokyo’s morning cash session runs until 11:30 JST, followed by afternoon trading from 12:30 to 15:30. The later closing value will determine whether Wednesday finishes above or below 63,484.10. This is an opening report with a timestamped follow-through observation, not a final close or a continuously updating quote.