Speculative grade
From ACT Wiki
Credit ratings
A rating attributed to a security that is deemed speculative (less certain in respect of the preservation of the capital invested) in the opinion of a credit rating agency such as Fitch Ratings, Moody’s or S&P (Standard and Poor’s).
Speculative grade represents credit ratings which are weaker than investment grade.
In Fitch and S&P's long term rating scales, speculative grade is BB and lower.
The equivalent in Moody's scale is Ba1 and lower.
Speculative grade is also known as 'sub-investment' grade, 'non-investment' grade, or sometimes 'spec' grade.