South Korea Paused Its Forced-Sale Rule, and the Kospi Still Fell 6%

Trading in Seoul lasted three minutes on Friday. At 9:03 a.m. local time the Kospi was down more than 8.5%, the first-stage circuit breaker kicked in, and the market stopped entirely for 20 minutes.

Thursday's brake was different: it paused only computer-driven sell orders for five minutes, while Friday halted everything. Korean media said it was the 11th first-stage circuit breaker this year, the previous one on October 15.

The Kospi hit 4,911 intraday, down 8.78%, and traded below 5,000 for the first time since February. It closed down 6.02% at 5,059.69, taking the two-day loss to 11%. The index lost about $197B (₩267 trillion) of market value in one day.

Foreigners did the selling again. BusinessKorea reported ₩2.77 trillion of net foreign sales, or $2.04B at 1,356.6 won per dollar, with $1.42B in SK Hynix alone. Institutions bought a net $1.26B and retail investors $443M.

Seoul and Tokyo Fell Harder Than New York

The chain started in New York on Thursday. After Senator Bernie Sanders called for a national data center moratorium, the Philadelphia Semiconductor Index fell 12.25%. Closing figures cited by Korean media show Micron down 17.5% and SanDisk down 22.3%.

In Tokyo the Nikkei 225 closed down 5.96% at 57,434.77, more than 20% below its June 22 peak, entering a bear market. IBTimes reported SoftBank Group down 15.8% at the open, Advantest down 12.2% and Tokyo Electron down 7.3%.

The Kospi's losses centered on two memory makers. Samsung Electronics lost 13.44% over two days and SK Hynix 18.91%. Both are tied directly to data center spending in the US.

Seoul Stopped the Obligation to Sell, Not the Selling

A circuit breaker pauses prices, so the government went after the cause of the selling. An emergency meeting chaired by Finance Minister Lee Hyeong-il began at 10:30 a.m.

The decision is a binding regulatory step. Brokers' obligation to keep a 140% collateral ratio on margin loans is waived for three months from November 9. Seoul Finance noted the waiver does not stop every forced sale; each broker decides how far to lower its line.

Past cases show the distinction. Under the same waiver in 2022, Mirae Asset cut its line from 140% to 130%, while some brokers merely delayed sales by one day. In March 2020 the waiver ran for six months.

The market read Friday's sell-off as a wave of fear. The government read it as a forced-sale chain in shares bought with borrowed money.

The Math of a Forced Sale

Buying on margin means paying for part of a stock with money borrowed from the broker. If the holding falls below 140% of the loan, the broker asks for more collateral; without it, the broker sells. More: What Is Leverage?

The problem is that forced sales happen at market prices. Each one pushes the price lower, and the lower price moves the next account toward its line. SK Hynix's 18.91% two-day loss shows the 30% line could be crossed on the next hard day.

The balances show the chain has already been running. Korea Financial Investment Association data show margin loans fell from a $28.5B peak on June 24 to $21.1B on November 4. The drop in the last three weeks alone was 16.5%.

What Does Not Fit the Story

The close shows a rebound of nearly three percentage points after the circuit breaker. Institutional buying of $1.26B was part of that recovery.

Foreigners, however, have sold for six straight sessions, a total of $8.84B. The waiver protects retail borrowers; it does nothing about foreign funds selling.

There is no binding step from the White House. According to Euronews, Trump posted on Thursday blaming the drop on the Democrats' election win. The sources reviewed show no administration action on a data center moratorium.

The chart is live and counts back from today; the framing above belongs to November 6.

What It Means for Investors

• The market priced the data center moratorium as a 2028 order risk, not as law; Seoul's selling is the most leveraged link in that chain.
• Micron, SanDisk and Nvidia depend on the same demand as SK Hynix, so Seoul's forced selling could feed back into them at the US open.
• The October jobs report is due at 8:30 a.m. ET (4:30 p.m. in Istanbul), with 65,000 jobs expected; a strong number raises the odds of a December hike.
• The risk to this reading is foreign selling stretching into a seventh day while brokers keep their lines unchanged.

This story is based on November 6 reports from BusinessKorea, Asia Economy, Korea JoongAng Daily, Herald Business, Seoul Finance and Digital Daily. Japanese figures come from IBTimes and Euronews, and the jobs forecast from Investing.com. Herald Business's foreign-flow figures conflicted with other sources and were not used. Dollar figures use the November 6 end-of-day exchange rate.