▁based ▁on ▁their ▁existing ▁hold ings . ▁In ▁both ▁stock ▁spl its ▁and ▁reverse ▁spl its , ▁the ▁share ▁price ▁is ▁adjust ed ▁in ▁proportion ▁to ▁the ▁increase ▁in ▁shares ▁to ▁maintain ▁equal ▁value . ▁ ▁As ▁an ▁example ▁of ▁how ▁reverse ▁spl its ▁work , ▁Pro Sh ares ▁Ul tr ash ort ▁Silver ▁( Z SL ) ▁under w ent ▁a ▁ 1 - 1 0 ▁reverse ▁split ▁on ▁April ▁ 1 5 , ▁ 2 0 1 0 , ▁which ▁grouped ▁every ▁ 1 0 ▁shares ▁into ▁one ▁share ; ▁accordingly , ▁this ▁multip lied ▁the ▁close ▁price ▁by ▁ 1 0 , ▁so ▁the ▁stock ▁finished ▁at ▁$ 3 6 . 4 5 ▁instead ▁of ▁$ 3 . 6 4 5 . ▁On ▁February ▁ 2 5 , ▁ 2 0 1 1 , ▁Z SL ▁had ▁a ▁ 1 - 4 ▁reverse ▁split ▁( every ▁ 4 ▁shares ▁became ▁one ▁share , ▁which ▁multip lied ▁the ▁close ▁price ▁by ▁ 4 , ▁to ▁$ 3 1 . 8 3 ). ▁Because ▁of ▁these ▁two ▁actions , ▁one ▁share ▁of ▁Z SL ▁as ▁of ▁February ▁ 2 6 , ▁ 2 0 1 1 ▁represents ▁ 4 0 ▁shares ▁of ▁Z SL ▁before ▁April ▁ 1 5 , ▁ 2 0 1 0 . ▁These ▁spl its ▁were ▁necessary ▁to ▁maintain ▁the ▁share ▁price ▁of ▁the ▁fund , ▁whose ▁value ▁fell ▁ 9 0 . 2 % ▁from ▁April ▁ 1 5 , ▁ 2 0 1 0 ▁to ▁April