(This version of the July 23 story corrects unit of upfront price in the final paragraph to “points” rather than “basis points”.)

FILE PHOTO: A row of new Tesla Model 3 electric vehicles is seen at a parking lot in Richmond, California, U.S. June 22, 2018. REUTERS/Stephen Lam/File Photo

NEW YORK (Reuters) - The amount investors must pay to insure their debt holdings in Tesla Inc TSLA.O against declining credit quality rose on Monday to its second-highest price ever, implying the company is at a greater risk of default following a report that sparked concern that Tesla may need to raise funds.

Insurance on Tesla’s debt, which is sold as a credit default swap contract, increased from Friday by 13 cents to $5.96 per $100 of Tesla debt. That followed a Wall Street Journal report on Sunday that Tesla had turned to some suppliers for a refund of previously made payments in a bid to make a profit, citing a memo sent by a Tesla global supply manager.

A Tesla spokesperson said on Monday that the company had no comment on the credit default swaps, but said in a statement in response to the WSJ story that Tesla had asked fewer than 10 suppliers to reduce capital expenditure project spending. Tesla said that any changes with these suppliers would improve future cash flows but not affect its ability to achieve profitability in the third quarter.

Company founder and Chief Executive Officer Elon Musk may be obligated to tap debt or equity markets again this year, according to analysts, though he has said he would do neither.

The market’s faith in Musk’s ability to raise cash if needed has kept Tesla’s implied risk of default lower than similarly rated junk bonds and has propped up the price of its debt, according to analysts.

Tesla's junk bond coming due in 2025 88160RAE1= fell 1.75 cents to trade as low as 88.875 cents on the dollar, its biggest drop since Moody's downgraded the company's senior notes to Caa1 following production delays.

It cost $5.96 to insure $100 of Tesla’s debt, plus an upfront cost of around 18 percent, representing a total of 24.1 percent of the face value of the 2025 bond on Monday.

“The CDS is saying that there are a lot of people betting this company is going out of business,” said Thomas Graff, head of fixed income at Brown Advisory.

Tesla has burned cash ramping up production of its Model 3 sedan, which prior to July, had fallen short of a series of targets.

Profitability has been elusive for Tesla. There is over $11.5 billion of short interest on Tesla’s shares, the largest of such positions in the U.S. market by dollar value, according to financial analytics firm S3 Partners.

A short position is a bet that a company’s shares will fall in price. Investors borrow shares in the hopes of selling them and then buying back shares at a lower price to repay the loan, allowing them to pocket the difference.

As a percentage of outstanding shares, Tesla’s short interest is 20.4 percent, which places it in the top 50 most shorted stocks on the Nasdaq.

The implied market probability of a default on Monday rose to 38.9 percent from 38.3 percent on Friday, according to Thomson Reuters Eikon. The probability of a default was 34.19 percent when the credit-default swap contract TSLA5YUSAX=MG, the first and only referencing a Tesla bond, launched on June 27.

Compared to Monday's swoon in the bond price, the increased default probability seems low. That is explained, however, by the illiquid state of Tesla's CDS, which have had only one trader, Edward Koo at JPMorgan JPM.N, regularly offering quotes on the swap, according to Reuters trading sources who requested anonymity because the quotes are not public.

Because it has become harder to find third parties who are willing to take on credit risk via CDS since the financial crisis, market makers sometimes have to absorb that risk themselves. That raises CDS prices.

But the opportunity offered by Monday’s falling bond price saw a market maker added to the mix, with Goldman Sachs quoting an upfront price of 18 basis points to buy debt protection, and 16 to sell, according to Reuters trading sources with access to the quotes. JPMorgan’s quote was 23 points for buyers, versus 18 for sellers, up a point for both parties from last Wednesday’s quote.