They raised money via debt, not an equity sale, right?

There’s no valuation when raising via debt, just an interest payment due.

Convertible notes are typically used to raise money quickly and also carry caps and discounts to the next funding round.

The last priced round was all for mining; basically every miner has gone belly-up over the last 12 months. I suspect this was bridge financing to cover cash after losses on mining hardware investments.