Final answer:
Under MM Proposition 1, Aussie Ltd's stock price should be the same as Kiwi Ltd's at $24 per share. If Aussie's equity is valued at $10 million, there is an opportunity for arbitrage. The optimal capital structure in MM perfect capital markets with no taxes is considered irrelevant.
Step-by-step explanation:
According to MM Proposition 1, the stock price for Aussie Ltd should remain the same as Kiwi Ltd, as the value of the firm is not affected by the financing mix used, given perfect capital markets with no taxes. Therefore, with 1 million shares outstanding and a share price of $24 per share, the equity value in both firms would be $24 million.
If the equity of Aussie Ltd was valued at $10 million, it would suggest the market is not adhering to MM Proposition 1. An investor should be indifferent about investing in either firm, as per MM's theory; however, if Aussie Ltd's equity is undervalued, there might be an opportunity for arbitrage. To achieve a 10% ownership stake in Aussie Ltd with mispriced equity, one could sell short 100,000 shares of Kiwi Ltd for $2.4 million, buy 100,000 shares of Aussie Ltd for $1 million, and lend out the remaining $1.4 million at the 5% interest rate, which would result in a riskless arbitrage profit.
In MM perfect capital markets with no taxes, the optimal capital structure is irrelevant since a firm's value is unaffected by how it is financed.