JPMorgan Chase & Co. , the bank’s parent, is of particular concern because in mandatory disclosures, that few journalists examine but our Jim Henry did, the company revealed it is on the hook to deliver more than 5,900 tons of silver it doesn’t have. Tradeable silver is relatively scarce right now, government data shows.

The bank sold contracts for silver it didn’t own, expecting the price would fall. Then it planned to buy the contracts back for less, making a profit by selling high and buying low. This risky practice is known as “short selling.”

Buying stocks or other assets and holding them in the hope the price will rise is called “going long,” which is what most investors do because its less risky.

JP Morgan got caught in a squeeze because the spot price of silver has nearly tripled since Donald Trump took office, creating an exposure that I calculate at up to $13.7 billion, roughly equal to the profits JP Morgan earns every 90 days, though likely just a costly fraction of that.