Basically, when a starbond has a big adjust coming up, a lot of traders will buy it (or short it). After the adjust many of these traders will liquidate the investment and realise their profits.
This is what's happening with KWIIG. She had a big adjust up on Tuesday, and a lot of traders bought the bond in the week or so before adjust. Now these traders are selling, causing a downward movement in price. Other traders have shorted KWIIG on the expectation that she will fall in price as other traders get out of the investment, which places more downward pressure on price.
Obviously, KWIIG will adjust up in 2 weeks when DATEN replaces GHSTW in her TAG, and if you stay the course you'll be rewarded with guaranteed profits. But two weeks can be a long time on HSX.