Leave the local shares. Take the ADRs.

One business day after celebrating the largest-ever debut for a foreign company in America, SK Hynix plunged the most on record in South Korea.

At the peak in June, the company was worth nearly $1.3 trillion. It’s shed more than $400 billion in market cap since.

The local shares, which closed more or less on the lows Monday, are down more than 35% in three weeks.

In addition to Monday’s 15.5% record-setting route, the shares suffered two additional double-digit, one-day declines since leveraged ETFs referencing single stocks won approval in May.

For at least the sixth time in four months, South Korean regulators suspended trading as simultaneous selloffs in SK Hynix and Samsung pressured the benchmark. Those two stocks alone account for more than half of Kospi market cap.

The figure below gives you a sense of the madness. Forget 5% swings: The Kospi’s moved at least 6% on more than a dozen occasions over the last five months, including multiple single-session swings exceeding 8%.

Not to be unduly derisive, but this looks increasingly like a lost cause. The decision to green-light the leveraged ETFs was a Pandora’s box.

Local officials have to rein this in somehow. Foreign investors are hitting the exits in droves. The Kospi risks becoming the exclusive domain of retail investors with gambling problems.

That’s an untenable proposition on its own, but when you consider how important Samsung and SK Hynix are in the global context thanks to the HBM supply story, it’s a total non-starter. Or should be. These are two mission-critical companies whose market value’s prone to swinging by 10% on a daily basis. (“GTFOH,” as the kids would say.)

Monday’s theatrics underscored the subtext of my remarks in and around SK Hynix’s US debut late last week. The ADRs are going to be a circus too.

Part of the problem to start the week were rumors suggesting the company might under-deliver on earnings due — ironically — to SK Hynix’s dominant position in HBM, which one brokerage suggested could be an albatross given slower price growth compared to “conventional chips.”

Other possible catalysts for the selloff included profit taking and, as one analyst put it, a “technical rotation into [the] ADRs.”