Alphavalue / Divacons| The UK-based chip design company is preparing its US IPO, which could come as early as September. Arm’s owner, Softbank, needs a high assessment to clean up its image after recent fiascos. The IPO could fetch a valuation of around €60 billion, the highest in the US this year. But the situation appears to be complex, given that the chipmaker’s main market has stopped growing, its model is in transition and it is embroiled in a legal battle with one of its main customers.