Anatomy of the One-Day Dump

01 · Frequency

Shallow dumps are routine. Deep ones are rare and specific.

A 20–30% intraday fade off the high happens to roughly one in five volatile small-caps — it is the ordinary texture of this market. Each extra 10% of depth cuts the population roughly in half. By −80% only a couple hundred events exist in ~34 months of data, and at −90% just 80. Everything below shows that these deep events are not "more of the same" — they are unique with a recognizable profile.

02 · Who they are

The deeper the dump, the more Chinese it gets

Chinese issuers make up 16.8% of the non-dump control population. Among shallow dumps they are barely over-represented (20%). But their share climbs monotonically with depth, and in the −90% bucket 50 of the 80 events are Chinese names. Deep dumps also carry the manipulation fingerprint regardless of country: no same-day news for about half of them, trading halts on most, SSR triggered on nearly all.

03 · The pump before the crash

They crash from the top of a months-long ramp

Deep dumpers do not fall out of nowhere. The median −80/−90% name enters its crash day after a +700–730% run over the prior trading year (Chinese −90% names: +1,246%), sitting at or near its yearly high, up 15–44% over just the last 20 days, on a rising streak of green closes. The grind is unusually orderly — 51% of the last 60 days closed green (vs 44% for shallow dumps) — and volume builds into the top (recent volume 2.6× its earlier average for d90). The final vertical leg is short: the deepest names spent a median of only 18–38 trading days above half of their crash-day high. Long quiet accumulation, a fast blow-off, then the rug.

04 · The day itself

High in the morning, destruction by the close

Across all depths the day high is set early — median around 7:00–7:30 ET, with 72–80% of highs printed in premarket. The low lands late: for −90% events the median low prints around 15:15–15:40 ET. The collapse is fast where it matters: a −90% dump is already down 50% about 2.4 hours after the high and down 80% in under 3 hours; the last leg to −90% takes longer because of repeated volatility halts (78% of d90 events halt at least once). After the low there is essentially no bounce — the median −90% event recovers just 3% of its fall range before the session ends.

05 · The aftermath

There is no recovery trade

Whatever the depth, the dump day is not the bottom — roughly 9 in 10 names print a new low within the next 60 trading days. Returns keep bleeding, and the deeper the dump, the worse the bleed: 60 days after a −90% event the median name is down another 72% from the dump-day close (Chinese names: −82%). "Recovered half the fall within 60 days" happens for 86% of shallow d20 fades — those are ordinary volatility — but for only 11% of −90% dumps, and 4% of the Chinese ones. Once the rug is pulled, the story is over.

06 · IPO & underwriters

The $4 IPO pipeline is real

For every symbol with a dump of −40% or worse (1,703 symbols; a CIK was found for all of them), we pulled the IPO date, IPO price and underwriters from SEC EDGAR. A quarter of these companies went public at about $4 — the Nasdaq listing minimum and the classic small-float China-IPO price point — and one in five dumped within its first year as a public company.

Underwriters split into two different worlds. The boutique circuit that brings $4 micro-caps public — Revere, D. Boral, Prime Number, Bancroft, Craft, WestPark, US Tiger, AC Sunshine — has heavy Chinese concentration and sees its IPOs dump within months. Bulge-bracket names (Goldman, Deutsche) also appear in the list, but their IPOs dump after a median of ~5–7 years with no China tilt — those are ordinary biotech and growth blow-ups, not pump schemes.

07 · Trend

Dumps aren't getting more common — but they're getting more Chinese

The share of volatile tapes that end in a dump has been flat at 18–22% for ~34 months. What moved is the mix: the Chinese share of dump days drifted from ~15–20% in 2024 to 25–32% through 2026, peaking at 32.4% in June 2026 — the same month that set the record for deep dumps (244 events of −50% or worse, versus ~40/month when the corpus starts in late 2023).