Taiwan's securities regulator cut the daily cap on short-sale orders by 90 percent on Nov. 6, 20261. The order came hours after the Taiex closed 10,267 points below its Oct. 6 high of 49,968.92, a drop of 20.55 percent3.
Three trading days later, on Nov. 9, the index closed at 41,661.70. That is a gain of 1,960.06 points, a 4.94 percent jump and the Taiex's second-largest point gain on record3. Taiwan Semiconductor Manufacturing Co. alone supplied about 800 of those points. One stock moved an entire index.
A Week That Erased a Fifth of the Market
The slide built for a month. Investors had spent October reassessing how much AI data-center spending the world's biggest tech buyers can sustain6. Then came the U.S. midterm elections on Nov. 3.
Voters handed power to candidates who had campaigned against unchecked AI growth. Traders read the result as a policy risk to the whole buildout. Markets had priced in an AI-friendly Congress all year, and Tuesday's result reversed that bet.
Taiwan felt it first. Its stock market carries the heaviest AI exposure of any in the world4. A doubt about AI spending anywhere lands hardest in Taipei.
By Nov. 5, the Taiex had fallen for six straight sessions, down 3.2 percent that day alone to 41,574.72. Foreign funds sold a net NT$102.46 billion of Taiwanese shares that single session. The selling came from outside money, beyond Taipei's own trading desks.
Nov. 6 was worse. The index opened down nearly 3,800 points intraday, touched a low of 37,837, and closed down 1,873.08 points, or 4.51 percent, at 39,701.6425. Five trading days had erased 5,510.19 points, 12.19 percent of the index's value.
Foreigners kept pulling money out through it all. October alone saw a record NT$994.316 billion leave Taiwanese shares, then another NT$524.4 billion in November's first six days.
That afternoon, Taiwan's National Financial Stabilization Fund held its 131st interim committee meeting2. Its members invoked Article 8 of the 2000 law that created the fund. Article 8 covers events that "significantly affect public confidence" and risk "disorder in the capital market." They cleared the fund's executive secretary to spend as needed, ahead of any second vote. The rescue marked the fund's tenth since its founding.
Taiwan's Taiex Falls 20 Percent, Then Jumps 4.9% in a Day
Taiex closing points, Oct. 6 to Nov. 9, 2026
The line follows the Taiex down from its Oct. 6 high to its Nov. 6 close, then back up to its Nov. 9 close; higher means the market gained, lower means it fell.
Sources: Ministry of Finance (Taiwan) [2]; Focus Taiwan [3]; Taipei Times [5]. Chart by Ryan Elliott Dennis.
The numbers behind this chart
| Period | Value |
|---|---|
| Oct. 6 high | 49,968.9 points |
| Nov. 6 close | 39,701.6 points |
| Nov. 9 close | 41,661.7 points |
Taiwan's Fix: Smaller Short Bets, a Bigger Buyer
The Financial Supervisory Commission paired the fund's rescue with a rule change, both effective Nov. 91. Daily short-sale orders on borrowed shares now cap at 3 percent of a stock's 30-day average volume, down from 30 percent. The minimum margin a short seller must post rose to 130 percent, up from 90 percent.
Regulators also told listed companies to consider buybacks and investor briefings, urging them to "exercise prudent investment strategies" as markets settled1. The fund itself can deploy up to NT$500 billion, about $15.2 billion, the same ceiling it has carried for a quarter-century2.
Wall Street felt the announcement first. TSMC trades in New York as an American depositary receipt. That stock jumped as much as 6.77 percent in Friday's premarket session7.
The jump came hours after Taiwan announced the curbs, a full trading day before the exchange itself opened under them. Taipei's own shares moved on Monday instead, once the new limits actually applied there.
Back in Taipei on Nov. 9, TSMC's locally listed shares rose 4.68 percent to NT$2,235.003. The stock makes up more than 40 percent of the Taiex's total value, so its gain carried the whole index. Trading that day ranged from 40,347.28 to 42,349.36, on turnover of NT$837.93 billion, about $25.51 billion.
TSMC Supplies 41 Percent of Monday's Taiex Rebound
Points of the Taiex's 1,960-point Nov. 9 gain, by source
Source: Focus Taiwan [3]. Chart by Ryan Elliott Dennis.
The numbers behind this chart
| Item | Value |
|---|---|
| TSMC's share of the gain | 800 points |
| Whole | 1,960.1 points |
Who's Buying, and Who's Still Selling
Hua Nan Securities analyst Kevin Su read Monday's bounce as confidence returning. "With the government's pledge to intervene in the market, investor sentiment improved, prompting many investors to buy on dips today," Su said3. Domestic retail buyers did exactly that, pushing the electronics index up 5.49 percent and the petrochemical sector up 7.40 percent.
Foreign institutional investors kept selling anyway, a net NT$90.06 billion the very day the index jumped3. That is the tell. The curbs changed who could sell short, and left the question of whether October's departing funds want back in unresolved.
UOB Asset Management Taiwan fund manager Kuo Hsiu-cheng named that deeper worry two days before the rescue. "Investors are reassessing the outlook for AI infrastructure investment following the US midterm elections on Tuesday, amid concerns that shifts in technology policy and regulatory priorities could slow the industry's expansion," Kuo said4. A short-sale cap leaves that question open. Only buyers can settle it.
Ed Yardeni, president of Yardeni Research, frames the larger debate over AI spending itself. "I think it's an AI bubble losing some air very, very rapidly, and I think that reduces the likelihood that we'll get a bursting bubble that has adverse consequences for the economy and broader financial system," Yardeni said6. Lin Wei-chih, executive vice president at the Zhi-Pu Industry Trend Research Institute, drew a narrower line for Taiwan's own market. "A change of party will cause a short-term market slump, but only a financial crisis will cause a crash," Lin said8.
What to Do
If your company's roadmap leans on TSMC-made chips, read Monday's bounce as relief. The curbs bought sellers time to catch their breath. They left untouched the question that started the slide: whether AI buyers keep ordering at October's pace.
Watch TSMC's own October sales report, due within days of this rally, before you budget around cheaper or scarcer chip supply. A revenue number beats a rule change for reading real demand.
By the numbers
- 90 percent: Taiwan's cut to daily short-sale orders, down from 30 percent of a stock's 30-day average volume, effective Nov. 91.
- 1,960.06 points: the Taiex's gain on Nov. 9, its second-largest point gain on record3.
- 130 percent: the new minimum margin for short sales, up from 90 percent1.
- 10,267 points: how far the Taiex fell from its Oct. 6 high to its Nov. 6 close, a 20.55 percent slide3.
- NT$500 billion: the stabilization fund's ceiling, about $15.2 billion, deployed for the tenth time since 20002.
- 800 points: TSMC's share of the Taiex's Monday gain, out of 1,960.06 total3.
- Net NT$90.06 billion: foreign investors' selling on the day the index rallied3.
What to watch
TSMC reports October revenue within days. Its revenue is the cleanest read on whether AI buyers are still ordering at the pace that justified the Taiex's October highs. Watch, too, whether foreign funds turn net buyers again.
A rally that foreign money keeps selling into shows the rule working, ahead of the worry actually resolving. Another stabilization fund rescue inside a month would say regulators doubt the first one held.
Sources
- Financial Supervisory Commission, "FSC Adjusts Daily Intraday Securities-Lending Short-Sale Order Caps and Margin Ratios," Financial Supervisory Commission (Taiwan), Nov. 6, 2026, https://www.fsc.gov.tw/ch/home.jsp?id=96&parentpath=0,2&mcustomize=news_view.jsp&dataserno=202611060002&dtable=News
- National Financial Stabilization Fund Management Committee, "National Financial Stabilization Fund Authorizes Market-Stabilization Task," Ministry of Finance (Taiwan), Nov. 6, 2026, https://www.mof.gov.tw/singlehtml/383?cntId=9f3f6bab54e44038b427386b8acc63fa
- Focus Taiwan, "Taiex Posts 2nd-Largest Daily Point Gain on Intervention Pledge," Focus Taiwan, Nov. 9, 2026, https://focustaiwan.tw/business/202611090017
- Taipei Times, "Shares Plunge 3.2%, Extending Losses," Taipei Times, Nov. 6, 2026, https://www.taipeitimes.com/News/biz/archives/2026/11/06/2003867229
- Taipei Times, "TAIEX Falls to No. 7 in the World in Market Cap," Taipei Times, Nov. 9, 2026, https://www.taipeitimes.com/News/biz/archives/2026/11/09/2003867383
- Yahoo Finance, "Stocks Plunge as AI Worries Crush Tech Shares," Yahoo Finance, Nov. 5, 2026, https://finance.yahoo.com/markets/stocks/articles/tech-stocks-plunge-worries-ai-153258250.html
- KuCoin News, "TSMC Rises 7% as Taiwan Restricts Short Selling Amid Semiconductor Market Volatility," KuCoin News, Nov. 6, 2026, https://www.kucoin.com/news/flash/tsmc-rises-7-as-taiwan-restricts-short-selling-amid-semiconductor-market-volatility
- BigGo Finance, "Taiwan's National Stabilization Fund Launches Tenth Market Rescue; TAIEX Surges Over 1,600 Points in Early Trading to Reclaim 41,000," BigGo Finance, Nov. 9, 2026, https://finance.biggo.com/news/49118b47-396f-43b0-8959-16472e0e1ee5
