My question is, who is buying what is being sold low?
At the moment, nobody because it's not an active asset on the Bitshares DEX yet.
Anyone can buy the low and settle the peak.
Someone who shorts the peak and buys back their debt at the trough can profit from debt destruction.
You may buy the peak and settle the next peak so as to keep 2x BTS locked up away from exchanges, the effect of liquid supply reduction is an unknown but people may have strategies around this.
Overall, it's an experiment and these answers are theoretical until it actually beings being traded & we see the reality of participant behaviour on the production network.