What is the main difference between held-to-maturity investments and trading securities?

Held-to-maturity investments are restricted to government bonds only, while trading securities include corporate bonds exclusively.

Held-to-maturity investments are intended to be held until maturity, while trading securities are bought and sold frequently.

Held-to-maturity investments are always purchased and sold at a premium, while trading securities are sold at discount prices.

Held-to-maturity investments are recorded at current fair value, while trading securities are recorded at historical cost.