The price rise is a direct result of three things:
Diminishing confidence in Tether
An increasingly ALT/Bitcoin bear market
The fact you can't buy bitusd on exchanges anymore.
People are hedging a crypto bear market with bitusd. Notice the uptick on bitusd volume and market cap the past 3 days.
If bitusd stays off of centralized exchanges, and bitusd gains more popularity and maintains the peg, expect Bitshares to be a sanctuary in a bear market. But, at the same time, expect it to fall back down when the bear market turns bullish.