Doing some simple math the GDXJ Net Assets.are US474m and Arizona is being added at a c.0.42% weight which implies a value of US$1,990,800 in the index. If we divide this by US share price of c.$4.00, thats 497,700 shares that need to be bought this week..Thats not insignificant volume given its normal voulme patterns. There will be index arb players trying to game this inclusion so expect unusual share price vol this week.