Two instrument available to be reported at fair value option:
Disclosures
Fair value, concentrations in credit risk (borrower defaulting), market risk (not required, only encouraged),
Trading securities
If current asset (like a trader) then CFO. All gains and losses go on the income statement unrealized or realized. Can also be non current asset, then would be CFI
AFS (Available for Sale)
CFI usually non-current. Mark it to fair value. If realized g/l goes on I/S. If unrealized goes on OCI.
HTM (DEBT)
Usually a bond. If you want, can classify as HTM. On CFI. Only HTM if has INTENT and ABILITY to hold this investment until Maturity.