SPDJI quoted $50,000 per month for a 'licensing fee - external use' for the 'official' index pricing when we reached out 6 months ago.
Turns out that's just for the trademark use (SP500, SPX etc) - even US-licensed DCMs have listed S&P products without using the name, without paying the fee. For example, Small Exchange had 'The 500'.
This seemed like a waste, so we decided not to go for it. Hence, our perp is just called 'US500', which is totally fine. Similarly, other exchanges like
@Dreamcash (USA500) and
@ostium (US500) are not doing anything wrong.
@tradexyz certainly doesn't own the exclusive right to list these perps.
They might own the exclusive right to call their product 'S&P 500' on the UI (in a perps dex context), but this still remains to be seen.