The US Trade Ledger — every US container gateway, every partner
country, every month. Census-recorded, AIS-verified.
The Shift
On the trailing edge of a ship’s rudder sits a second, tiny rudder —
the trim tab. It is the answer to a hard problem: no one can push a loaded ship, and at speed
no one can even push the rudder against the sea. So you push the tab. The tab swings the
rudder, the rudder swings the ship. A small, exact force at the one surface where it
compounds.
The helmsman cannot push the ship, and cannot even
push the rudder against the sea. He moves the tab; the water does the rest — tab turns
rudder, rudder turns ship. Buckminster Fuller asked for it as his epitaph:
“Call me Trimtab.”
Everything below is trim-tab physics at trade scale. A few pages in the Federal
Register redirected two million tonnes of cargo a year from one country to another. A one-page
queuing memo moved a hundred-ship queue over the horizon. Three days of a strike bent a
coastline’s arrivals in half. Eight years of US containerised imports, twelve origin
countries, one moving picture: each bubble a country — how much it ships (across, log
scale), how fast that is changing (up and down). Scroll, and the story advances through every
shock the Event Atlas has ruled on. The ledger’s job is to find the
tab, measure the swing, and print it — including the times someone turned the wheel and
the ship did not move.
The steady state
June 2018. China is not a bubble among bubbles — it is the plot. More containerised tonnage than the next eleven origins combined, growing mid-single digits, unchallenged. Hold this frame; nothing after it looks like this again.
The front-run
Washington announces the List 3 tariffs in September; importers race the deadline. December 2018: China spikes to +25% — 1,147 kt above its counterfactual — cargo borrowed from 2019, not created. Read the ruled study →
The slide, and the mirror image
The bill comes due. Through 2019 China sinks — −35% by December — while Vietnam runs +48% in the exact months China craters. Watch the two bubbles cross vertically: that mirror image is trade diversion, drawn by the data. Read the ruled study →
The crater
March 2020: China −42% while total imports fall only a tenth — a supply shock with one address. Every other bubble barely trembles. It is the deepest single-origin plunge on the whole eight-year plot. Read the ruled study →
The everything boom
Locked-down America pivots its spending to goods, and every bubble lifts at once — China +29%, the whole field climbing. Offstage, the physics is already straining: LA’s anchorage hours double in October 2020 and never look back. Read the ruled study →
The great queue
October 2021: the boom has outrun the piers. Container ships log ~39,000 hours a month waiting at anchor off LA–Long Beach — six times normal. (In January 2022 the queue will vanish from harbour view. It didn’t shrink; a new rule hid it 150 miles offshore.) Read the ruled study →
The unwind
The goods binge ends as fast as it began. Berth hours at LA–Long Beach fall 59% in seven months and the census curve falls with them, point for point. Every bubble sinks below the zero line together — the only synchronized collapse on the plot. Read the ruled study →
The crisis that left no trace
Missiles close the Red Sea; Suez transits collapse; headlines predict chaos at US ports. The plot shrugs. Coast shares hold 56–59%, flat through the whole window. We publish the miss as prominently as the hits — the null is the method working. Read the ruled study →
Three days, visible from orbit
September 2024: importers front-run an East Coast strike — 56 berthings in a single day on September 25, then one, two and five as the coast shuts October 1–3. At monthly grain it is a smudge; ship-by-ship it is unmistakable. Read the ruled study →
Liberation Day, and the 50%
The 2025 tariff wave hits the two biggest Asian origins at once. China sinks to −29%. India front-runs +21 points above counterfactual in August — then falls through the floor and stays there: eight straight months suppressed, ~1.5 Mt short. Not borrowing. Suppression. Read the ruled study →
Where it stands
Eight years on, the steady state is gone for good: China’s share of containerised imports fell at every single US gateway — no exceptions — while Vietnam and India carry multiples of their 2018 tonnage. The realignment was not one event. It was all of them, compounding.
The builder
Trimtab is built and run by one person.
Mrigank Singh operates an India–US freight
forwarder by day and builds these instruments because he believes the trim-tab premise applies
to observation too: one builder, two instruments made of different machinery, and the
discipline to publish the nulls, can move how a trillion-dollar system is understood —
without owning a newsroom, a terminal, or a satellite. The forwarding business is an economic
interest in this subject, stated here rather than buried: findings that flatter it get more
scrutiny before publication, not less. Every claim on this site ships with the test that would
kill it. That is the small force, exactly placed.
In print: “The Shift” — eight years of US import
realignment (2018–2026), from US Census port-level records mirrored
and archived by the Trimtab US Trade Ledger — trimtabist.com For the record: data TT-008 · narration: Event Atlas, ruled studies ·
latest month 2026-05
Every figure in the narration links to its pre-registered study. The chart data
updates monthly as Census publishes; the rulings do not move.
All studies →