Late Wednesday, Mr. Romney won the support of uber GOP donor Paul Singer, who was considered to be one of the most sought-after undecided Republican fund-raisers. In the 2010 election season, Mr. Singer and his employees at Elliott Management donated $2.6 million to the Republican Governors Association, making the hedge fund’s employees the second-largest corporate donor of the campaign cycle.

In a letter, Mr. Singer called Mr. Romney “the best choice” among Republican candidates. He said his debate performances have been “impressive–fluid and at times commanding.”…

Prominent hedge-fund manager Daniel Loeb has decided to back Mr. Romney, according to people familiar with the matter, while a number of other key figures in the hedge-fund world are said to be making up their minds about who they will support. That list includes fund managers such as Cliff Asness, Steven Cohen, Ken Griffin, and Leon Cooperman. Anthony Scaramucci, who is raising money for Mr. Romney on Wall Street, said he expects many of the key financiers to support his candidate, “whether it’s today, two months from today, or nine months from today.