Is there any standard way to identify whether an SGB is undervalued?

I had a question regarding SGB pricing.

Do you guys consider theoretical value vs market price before buying? I’ve noticed sometimes bonds trade at a discount, but I wasn’t tracking it earlier.

Recently started using a simple tracker (SGB Gold) to compare values — seems helpful.

Would like to know if experienced investors here actively track this or just buy based on gold price.

You may refer to this site for hunting sgbs at discount… although most of the sgbs trade at premium after new issues have stopped since 2023.