As to taking over companies like that, no, it really is nearly impossible. For one, in order to get 51% of shares, they’d either have to have the company agree to it, or they’d need to purchase all the shares on the open market. When someone is looking to buy in bulk on the stock market, they tend not to get a discount: indeed, prices go up on a buy order that large.

They’d of paid $187 billion just for Toyota’s shares under the circumstances. Also, ever since the days of corporate raiders in the 1980s, most companies allow major shareholders to either purchase from the company or simply receive enough stock to maintain their percentage of ownership in a company in the event the company decides to issue more stock. I’m pretty sure this also applies to when a large purchase is made on the open market, as a way of fighting hostile takeovers. In this case, Teramento would’ve had to deal with the largest investors and company executives buying up shares directly from the company, decreasing the percentage Teramento could own.

Hence it would likely be more than $187 billion for Toyota. The only time a company is attractive for hostile takeover anymore is when its stock price is depressed and the company is in serious financial straights: at which point someone may buy it and then try and turn it around.

And forget buying Sony, or Mitsubishi. Here in America they are considered large companies, but both function at the conglomerate level internationally. Like hell anyone could take that over. Maybe the combined efforts of the all the midsize to large Private Equity firms in the world could do it, but there simply is not the capital to just acquire global conglomerates like that.