FILE PHOTO: The logo of Tesla is seen in Taipei, Taiwan August 11, 2017. REUTERS/Tyrone Siu/File Photo

(Reuters) - Investors are demanding a record risk premium for holding Tesla Inc’s $1.8 billion junk bond after the electric car maker posted a $700 million first-quarter loss and signaled it may be in the market for more capital soon.

The price on Tesla’s 5.3% note due August 2025 slipped, nudging its yield to the highest in about six months at 8.51% in European trading.

Its spread, the measure of the premium in yield investors demand for the added risk of holding a bond from Tesla - rated six notches below investment grade by Standard & Poor’s and Moody’s - rather than a safer U.S. Treasury security, widened by 3 basis points to a record 618 basis points.

By comparison, the spread on an average high-yield bond is 373 basis points, according to ICE BAML Index data, and for comparably rated “B-” issuers it is 402 basis points.