Last week, President Trump claimed a secret US mission had moved 100 million barrels of oil through the Strait of Hormuz while it was blockaded. The claim landed in an industry already consumed by the question of how much oil is actually getting out—and nobody, it turns out, can answer that with confidence.

No one’s experienced this kind of disruption,” said Matt Stanley, head of market engagement at Kpler, the commodity intelligence and ship-tracking firm. The reason the numbers are so hard to pin down is what the industry calls the dark trade—vessels running without their AIS transponders on, moving at night, closer to the Omani border, sometimes with naval escort.

There are ways to detect portions of outgoing oil anyway. Different grades of crude can only originate from specific fields. The UAE’s Murban crude can be exported via Fujairah, outside the strait. Another type of crude, Upper Zakum, cannot. One oil market analyst noted that their team has seen Upper Zakum crude oil appear in other markets. Those sightings are happening, yet the scale remains unknown.

Why Prices Haven’t Exploded Yet

The world’s most important oil chokepoint has been effectively shut for more than 100 days. World Trade Organization data shows a 95 percent reduction in crude oil shipments from Arabian Gulf ports and a 99 percent reduction in liquified natural gas carriers. The International Energy Agency has called it “the largest supply disruption in the history of the global oil market.” Yet Brent crude sits at $87.55 per barrel—the lowest since before the conflict began.

This is because of buffers. China has approximately 1.3 billion barrels in storage, drawing it down at around a million barrels a day, Stanley says. “We see their demand, about 7 million barrels a day from May, June, and July. They were buying 12.5 million barrels a day in December.” The US, Brazil, and Canada have also stepped in to fill part of the void.

The three analysts interviewed agree that the oil market’s response has been robust. “The oil market responded to this outage significantly well in terms of cutting parts of demand,” says Iman Nasseri, managing director, Middle East of FGE NexantECA, an energy and chemical advisory company. “There is also a significant amount of stock that has come to market, but we doubt that they will continue to do that. We expect that by July [if the strait remains closed], things will change.”