Justa,
Re the xau vs hui, they go up and down in very similar patterns, but end up in different places. I realize that is because they have different holdings, but I can't look at those and understand the details, since I don't know the names that come up. Both looked mostly like miners to me, checking just a couple names. (I could learn, but that is similar to work^*.) Could you provide a primary example of what one holds that the other does not and circumstances in which that makes it move more in some environments and less in others (even if the direction of the move is always the same)? Phew, harder to ask than answer, I think. Hey, I don't want to presume on your generous nature, so leave this till you get really bored someday -- .
Meantime, barkeep, I'll buy a round -- .
MP
^* PS: In another context, I once said something about work to my retired brother, and he replied: "Work? Work? Ah, I remember that that is something that seriously interferes with one's leisure time."
PPS: I did come across some articles about a hui vs xau strategy, playing the (undefined for me) differences.