The failed corner of which company's stock helped trigger the Panic of 1907?

The failed corner of United Copper Company stock helped trigger the Panic of 1907.

In October 1907, speculator Otto Heinze attempted to force a short squeeze in United Copper, believing the Heinze family controlled most of the company’s shares. The plan depended on locating and compelling short sellers to buy back borrowed shares at prices set by the cornering group.

The scheme quickly failed. United Copper rose sharply on October 14, but short sellers found shares elsewhere, undermining the squeeze. The stock then collapsed from about $60 to $10 within days. Banks and trust companies connected to Heinze, Charles W. Morse, and the financing of the speculation suffered runs as depositors and other lenders lost confidence.

The collapse did not by itself create every weakness in the financial system, but it was the immediate spark. The resulting runs spread to the Knickerbocker Trust Company and other institutions, turning a failed stock manipulation into a national banking panic.