Uncertainty in H100 rental rates by late September 2026 stems primarily from the accelerating shift toward NVIDIA's Blackwell architecture, whose wider availability and superior efficiency could redirect demand away from Hopper-generation GPUs and exert downward pressure on spot and cloud rental prices. Hyperscaler capacity expansions, ongoing large language model training runs, and power-constrained data center utilization remain key swing factors, while any delays in Blackwell deployments or sudden spikes in inference workloads could support prices in the $2.75–$3.00 range. Trader positioning reflects these competing supply and demand dynamics, with the current distribution underscoring how quickly new silicon releases and enterprise AI spending patterns can reshape the short-term compute market.