See attached chart. We are referring to financial swaps that settle against the power prices. Low that day in PJM was in the neighborhood of $107/mw , and we topped out around $300/mw.
The multiplier on this contract is $800, therefore, just buying one contract could've yielded $150k (approx). Bid-Ask spreads get ridiculous, and PnL can swings are massive if you have any sort of size on.
Oh yeah, and $120 calls traded $6 on Monday night.