The subject line is a bit misleading. Nat gas dropped from about $13 last June to the current three bucks. But still, who'd have thunk it...

Meanwhile the HNU leveraged ETF did indeed drop from $188 to $2.93.

"...I think the HNU shares did some sort of adjustment (I remember reading somewhere) so the share price may be a little skewed. ..."

Yes, there was a one for four reverse split on April 15 this year. The share price was slipping below two bucks, and the reverse split brought it back up to seven and change. That $188 high is correct as the "adjusted" price. HNU, along with HOU, demonstrates the effect that erosion can have when a leveraged ETF is held for a long period.