A luxurious Miami estate with roots in the legendary Howard Hughes's land holdings has been listed for $55.5 million.

Shares of Howard Hughes Holdings jumped after hedge-fund manager Bill Ackman's firm offered to buy 11.8 million Howard Hughes shares at $85 apiece to own a majority stake in the company. The stock jumped about 9.

Pershing Square Capital Management LP has proposed a deal to merge one of its subsidiaries with real estate company Howard Hughes Holdings Inc., according to a letter to investors.

Under the proposed deal, a Pershing Square unit will buy 11.8 million shares for $1 billion from non-Pershing Square affiliate shareholders of Howard Hughes, while the real estate developer will commence a $500 million share repurchase at $85 per share for up to 5.9 million shares.

Pershing Square's potential majority stake could influence Howard Hughes' future, but risks remain. See my recommendation on HHH stock.