BTW, you mention the "interest rate" on those bonds when I think you meant yield. Very big difference.
I'm not very knowledgeable here, but is the key difference that yield is more a result of the market (i.e. bonds fluxuate in value but the return on the bond itself is fixed, so the yield reflects the relationship between cost and payout)?
There is a "coupon", which is the amount a bond pays each year. Which is one kind of interest rate.
There is the "yield to maturity", and since Tesla's 2025 bond seems like a normal bond, so Yield implies yield-to-maturity. This is another "interest rate" but just saying "interest rate" is meaningless.
Since coupon vs yield is ambiguous, I should have used more precise language earlier.
> bonds fluxuate in value but the return on the bond itself is fixed, so the yield reflects the relationship between cost and payout
Yes.
I wouldn't normally refer to the return as "fixed" as that is primarily only used in reference to the coupon and because of the fact that you mentioned earlier in that sentence; bonds fluctuate in price so the yield is regularly changing given a change in price.
Instead, we can look at the Bond market for that. Moody's rates Tesla 2025 bonds at Caa1, and today the interest rate on Tesla has risen above 8.8%
The bond market certainly is pricing in the risk of default and/or bankruptcy at this point. 9%ish bonds are really bad on a 7-year bond, especially in today's market that's got relatively low-interest rate.