So tell me how does a short squeeze occur in your world? I'll tell you how it happens in the real world, there are people with short positions in the market, longs hold there shares, new money comes in via longs adding or sideline folks, PPS goes up, shorts start have an unrealized loss once the PPS goes up, once the PPS goes too high they must cover and realize their short position before they are forced to over at a much higher PPS. Since XUII is trading close it it's 52 week high of .44, we can be sure that at .45 all shorts are holding a losing position, and that's when the fun will start.
Yes volume is a good indicator, but not in the way you mentioned. Volume in terms of percent of O/S doesn't tell me much, I care about the volume in dollars and if we are setting new volume highs for the month average volume.
All my posts are nothing more than my opinion. Please, do your research of fundamentals, technicals, and due diligence before investing in any stock -especially penny stocks as they are extremely volatile.