takeover rules

Its not 15% its 19.9% thereafter you have to make a bid for all the shares at the same price for all.. It does not need to be approved by the target company board, hence there are often hostile offers ie offers not recommended by the board as is the case here with Allegiance. ZFX does not Allegiances board approval to succeed although it obviously helps as shareholders typcially do as the board suggests but not always. At 5% level you have to disclose you are a substantial shareholder. The only relevance of the 15% level is if you are a foreign bidder you will need FIRB (treasurers) approval to move beyond 15% eg Shell / Woodside which was rejected by FIRB>