Tesla shares are having their worst day of trading in over two years amid new alarming antics from CEO Elon Musk and executive departures.

But the bigger problem for the company may be the trading in its bonds.

"It's the bondholders who matter, not the stockholders, and the bonds keep going down," CNBC's said on "Squawk on the Street."

Tesla's 2025 bonds dropped on Friday to an all-time low of 82.03 cents on the dollar, down from 93 cents on the dollar on Aug. 7 — the day Musk announced he had secured funding to take Tesla private. The drop raised the bond's yield to 8.89 percent. (Bond prices move inversely to yields.)

The electric automaker has $9.5 billion in long-term debt as of the end of the June quarter. Credit ratings agency Moody's most recently lowered its outlook on Tesla's situation to negative from stable, citing "significant shortfall" in the Model 3 production rate and a tight financial situation.

"I don't even look at the stock anymore, because that's emotional. I look at the 2025 bonds, and I look at it incessantly," Cramer said.