[Nikkei Recap] Sep 16, 2026: Nikkei 225 Rebounds 439 Points to 63,923 as Chip Equipment Makers Surge, Mercari Slides 6%

Hey everyone, Hirokichi here. Let’s take a look at how the Tokyo stock market did today, September 16 (Wednesday). Bottom line: the Nikkei 225 rebounded 439 points to close at 63,923, and it actually closed at the day’s high. But the move wasn’t a simple across-the-board rally — chip equipment makers took center stage while the Growth market sold off hard, so today’s action was pretty mixed under the surface. Let’s dig into why.

Today’s index moves

Here’s a summary of the major indexes at the close.

What jumps out from this table is a “twist”: large-cap-heavy indexes like the Nikkei and TOPIX rose solidly, while the Growth 250, which tracks smaller growth names, dropped more than 2%. On the Tokyo Stock Exchange Prime market, 67.4% of stocks rose versus 29.0% that fell, so buyers were in control overall. Turnover came to 6.7075 trillion yen on volume of 1.76909 billion shares — busier than a typical day.

Looking at the last five trading sessions, the Nikkei fell for four straight days from the 65,270 level on September 10 down to 63,484 on September 15, before finally stopping the slide and bouncing back today. This chart makes it pretty clear that today’s 439-point gain was a breather within a week-long downtrend rather than a fresh breakout.

The Nikkei actually opened higher, up 188 points at 63,672, but the gains didn’t hold and the index slipped to as low as 63,209 by 10:56am. Buying picked up again in the afternoon session, though, and the index kept grinding higher into the close, eventually finishing right at the day’s high of 63,923. It was a classic “quiet morning, strong afternoon” session.

Why it moved: what drove the market today

There are three things worth understanding about today’s action.

(1) US stocks fell the previous session (Sep 15). The Dow closed down 328.09 points at 52,093.11. Rising oil prices continued to weigh on sentiment, lingering concerns about a slowdown in AI development kept selling pressure alive, and growing expectations for a rate hike at this month’s Fed meeting (FOMC) pushed the 10-year Treasury yield to its highest level since 2007 — all of which weighed on investors.

(2) Money flows within AI-related stocks are shifting. US AI startup Anthropic is reportedly eyeing a Nasdaq listing as early as mid-to-late October, and that prospect is starting to reshape where investment money goes. The trigger was a blog post over the weekend (the 12th) from Anthropic CEO Dario Amodei, in which he suggested AI development needs to slow down. OpenAI CEO Sam Altman and Tesla’s Elon Musk echoed similar sentiments, and on Monday the 14th (US time), the Philadelphia Semiconductor Index (SOX) tumbled 5.85%. That knocked chip equipment giants Tokyo Electron and Advantest into opening lower in Tokyo this morning.

(3) But domestic buy-the-dip flows picked up in the afternoon. After four straight days of declines had brought valuations down, a rally in South Korea’s KOSPI index also provided support, and bargain hunters stepped in. That’s the backdrop for the “strong afternoon” pattern mentioned above. By sector, Oil & Coal Products (+4.62%), Mining (+3.15%), and Textiles (+2.02%) — resource and materials names — led the gainers, while Pharmaceuticals (-0.90%), Info & Communications (-0.80%), and Airlines (-0.70%) topped the decliners.

Today’s featured stocks and why they moved

Let’s look at four stocks with notable moves today — what happened, and why.

This chart makes the contrast obvious at a glance: the two chip equipment makers finished in positive territory, while SoftBank Group and Mercari both ended deep in the red.

Tokyo Electron (8035) and Advantest (6857): chip equipment makers stage a comeback

Advantest, which commands over 50% of the global market for semiconductor test equipment, was the single biggest contributor to the Nikkei’s gain today, adding 130.33 points — the top spot among all 225 constituents. Tokyo Electron was right behind in second place, adding 104.59 points. Looking only at this morning’s price action, though, this outcome wasn’t easy to predict. As mentioned above, both stocks opened lower in Tokyo, carrying over the shock from the SOX index’s 5.85% plunge in the US the previous session. So why the sharp reversal? With share prices already down after four straight losing sessions, and with the underlying view that AI-related capital spending demand hasn’t actually disappeared, bargain hunters stepped in on the dip. Chip stocks have been swinging wildly lately, and I think we’ll keep seeing these “surprise open, surprise close” reversals for a while.

SoftBank Group (9984): lingering caution around AI-related holdings

SoftBank Group was the single biggest drag on the Nikkei today, subtracting 77.23 points — the largest negative contribution among all 225 constituents. The stock is still working through the aftershock of last week’s sharp decline, which was triggered on the 14th by reports that OpenAI CEO Sam Altman had denied plans for an IPO this year. Shares tried to bounce off their 25-day moving average today but couldn’t hold onto the gains, finishing lower. Given how heavily SoftBank Group is invested in AI-related companies, its stock tends to be highly sensitive to shifts in sentiment across the broader AI sector.

Mercari (4385): shares tumble on Pokémon Card listing ban

Mercari posted the sharpest decline of the day, falling 6.36%. The trigger was news released on the 15th: the company announced it would temporarily ban listings of items related to the “30th CELEBRATION” Pokémon Card set starting on the 16th, citing concerns about maintaining trust and safety on its marketplace. Since restricting a popular category can directly affect transaction volume, the announcement sparked selling from investors worried about the impact on earnings. It was a good reminder of just how sensitive a flea-market app’s stock price can be to a single operational decision about one product category.

What this means for individual investors

If you’re steadily building a position through regular investing, there’s no need to get worked up over a single day’s 439-point swing either way — that’s my basic take. Looking at the last five sessions, the Nikkei has still been going back and forth in the low-to-mid 63,000s, so it’s too early to say a clear new direction has been set. What stood out to me more today was how different the “winners” and “losers” looked underneath the surface. The chip equipment rally was really a bounce-back from the prior day’s slump, the TOPIX gain was underpinned by a rotation into resource and materials names, and meanwhile the Growth 250 dropped over 2% — so the outcome varied a lot depending on theme and market-cap size. If you’re trading individual names short-term, I’d say it makes more sense right now to focus on which theme or sector your holdings belong to, rather than just watching the overall index direction.

What to watch from tomorrow

(1) Whether the shift in money flows around AI-related stocks tied to Anthropic’s IPO speculation continues. It’s worth watching whether the rotation away from “pick-and-shovel” hardware names like chip equipment makers and toward AI solution stocks turns out to be temporary or a more lasting thematic shift. (2) The outcome of the Fed’s FOMC meeting and the tone of the press conference that follows — depending on where long-term yields head, there could be continued knock-on effects for currencies and high-multiple tech names. (3) Timing of any recovery in the Growth market — after today’s sharp sell-off, it’s worth watching whether bargain hunters step in there too.

Let’s keep at it, slow and steady. See you tomorrow!

* This article is for informational purposes only and does not recommend any specific investment. Please make investment decisions at your own responsibility.

For yesterday’s recap, check out the September 15 daily wrap-up as well.

日本語版はこちら → https://hirokichiiii.com/投資のいろは/nikkei-daily-2026-09-16/

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