[ghaff]

When people consent to variable rates, absent a cap they're making at least implicit assumptions about the likelihood and magnitude of rate spikes. By and large, people don't hedge variable rate loans, fuel oil prices (although some do), power rates, etc. But people (reasonably) assume that variable rate loan isn't going to spike to 50% interest some night. But as you say, I'm pretty sure that no one signing up for one of these plans imagined a 100x spike in their monthly electrical bill was a possibility.