Great question! I have been thinking about this. Reminds me of how Enron's traders would cause rolling blackouts in CA to drive up electricity prices. The current implementation winsorizes outliers but that isn't enough. Some fixes I see going forward
1. Implement additional providers and perhaps weight their contribution to the index by their inventory (harder for small providers to cause massive swings)
2. Use a Time-weighted settlement over 1-4hr periods to prevent rapid changes in spot
3. Verify data with bulk gpu compute marketplaces like ComputeExchange
4. Have third party services verify/or require some kind of "proof of rental" that gets sent to a registry. WTI/Brent has Platts and Argus that are price reporters who cross validate (similar mental model)
Do you have any more info on manipulating GPU rental prices? I would like to read more on that.