Soros disclosed he owns about 17.4 million shares of the Plano, Texas, department store operator in a filing with the Securities and Exchange Commission. The SEC requires shareholders to disclose stakes of 5 percent or more in a company.
JC Penney had no comment.
JCP shares jumped 7 percent after-hours following the news. (Click here to get the latest quote.)
JC Penney earlier this month fired its CEO, Ron Johnson, after 17 months on the job and rehired his predecessor Mike Ullman. An ambitious turnaround plan by Johnson had backfired and caused sales to plummet.
The chain has been burning through cash. The company last week said it would draw $850 million from its $1.85 billion revolving credit line to pay for replenishing inventory, particularly for its overhauled home area.
The stake makes Soros the fourth largest shareholder in JC Penney. The top shareholder is activist investor William Ackman's Pershing Square Capital, with a 17.8 percent stake.