Chesapeake Energy Corporation (NYSE:CHK) shares plunged by more than 50% to as low as $1.51 after the company announced that it has hired lawyers to assist it in restructuring. The embattled energy giant’s bonds also plunged today, and its stock had fallen by 85% over the last year not counting today’s massive decline. Thus far today, Chesapeake is the S&P 500’s worst-performing stock.

Chesapeake Energy Corporation Loses Half Its Value On Restructuring News

Chesapeake Energy said to be restructuring

According to Bloomberg, Debtwire reported today that Chesapeake has retained law firm Kirkland & Ellis to assist in in restructuring its massive debt pile of $9.8 billion, although CNBC pegs the amount of debt at more than $10 billion. The company has been embroiled in problems over the last several years with numerous legal problems and, more recently, tumbling energy prices that have weighed heavily on the Energy sector as a whole.

Chesapeake Energy is expected to post another annual loss this year, marking the second in the row, as a result over an oversupply on gas in North America. The oversupply has dragged prices down and reduced the company’s cash flows, which it had been dependent upon to pay back its debts, says Bloomberg. The company is set to release the earnings results for the fourth quarter and for 2015 on Feb. 24.

Chesapeake Energy’s bonds plummet

Chesapeake’s bonds weighed heavily on the high-yield debt market today, leading the losses in the market. The firm’s March 2016 notes fell to 74.5 cents, marking a record decline, according to Bloomberg. Last week the notes were trading at 95 cents. The 2017 notes plunged to 34 cents—a record low.

Last month, Standard & Poor’s cut Chesapeake Energy’s credit rating to CCC+ and gave a negative outlook as the credit rating agency expects gas and oil prices to remain low for quite some time. Further, the agency said Chesapeake’s debt leverage isn’t sustainable. Of the $9.8 billion in debt, $1.3 billion of it is due by the end of 2017.

Icahn, Longleaf hit by Chesapeake

Last month, shares fell to their lowest level since 2003, probably hitting activist investor Carl Icahn hard as he held more than 73 million shares as of the end of the third quarter. His fourth quarter holdings in the energy giant have not yet been reported, so we don’t know whether he exited some or all of his stake.

We do know from Longleaf Partners’ fourth quarter investor letter, which was review that it still held a significant stake in Chesapeake Energy during the fourth quarter, which weighed heavily on its returns.