Tesla share prices bounced a bit today but red lights are still flashing about Tesla's ability to pay back a monstrous pile of debt.

So Forget the Stock, Watch the Bonds.

$1.8 billion of Tesla bonds due in August 2025 plunged to a record low on Friday. The bonds traded for just 84 cents on the dollar, down from 98 cents a year ago. The yield, which moves opposite price, almost doubled over that span to 8.6%.

"Tesla is in a cash pinch," Cowen & Co. analyst Jeffrey Osborne said in an interview. "The primary concern — above and beyond doing drugs and whatnot on podcasts — continues to be the ability of the company to generate cash."

More than $9 billion of Tesla's debt is scheduled to mature before 2025, including a total of $2.7 billion this year and next, according to a Goldman Sachs research report that called the company's balance sheet "concerning."