I was wondering if this could be a contributing factor. There is almost unlimited demand for training models - and a lot of value to derived from doing so - and it seems like a perfect workload for spot.
I have just purchased 5% of a data center's Deep Learning servers. 10 GPU / 384 GB of RAM, 2 x Xeon 10-Core processors. I am putting them in a solar powered data center and plan to lease them out at $0.2 per GPU hour.