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Professional golfer Phil Mickelson, reportedly the subject on an insider trading investigation
The Journal's report said the authorities are examining whether Mickelson, a 3-time Masters champion, and Walters, a Las Vegas-based sports gambler, traded on information given to them by Icahn regarding about his investments.
The report focuses on trades made in Clorox in 2011.
Icahn and Mickelson are names familiar to anybody that follows business or golf, and perhaps both, but Walters' mention in this group has many asking, "who is that guy?"
The Journal reported on Sunday that their own story has caused a snag in the authorities' investigation.
This story is obviously far from over, so as we start the first work week since the story broke, here's what we know so far.
Carl Icahn
Carl Icahn is a famous hedge fund manager and activist investor. Icahn rose to prominence in the 1980s as "corporate raider," taking stakes in companies and agitating for change.
Icahn still employs similar tactics today.
Some of Icahn's most notable recent corporate fights have been in Herbalife, a multi-level marketing company that sells nutritional supplement shakes, Apple, and Dell.
Phil Mickelson
Phil Mickelson is one of the most successful golfers of his generation. Mickelson, who was Tiger Woods' chief rival for most of the mid-00s, has won 5 "major" championships, including 3 Masters Tournament's, considered by many to be the most prestigious golf tournament in the world.
Mickelson was confronted by FBI agents after his round at a golf tournament on Thursday, but instructed the agents to speak to his lawyers, according to The New York Times and The Journal.
The same report from the New York Times said that Mickelson first spoke to regulators regarding the probe last year after a Mickelson landed at New Jersey's Teterboro Airport. During that meeting, The Times said, Mickelson met with regulators for "no more than an hour."
Mickelson finished tied for 51st at this week's tournament, and ESPN notes that Mickelson, "is essentially having the worst season of his 22-year professional career."
Mickelson told reporters at a tournament in Ohio this weekend that he has done "absolutely nothing wrong," according to ESPN.
CBS / 60 Minutes Billy Walters
Most of what we know about Billy Walters is from this 60 Minutes profile in 2011. At the end of the profile, CBS' Lara Logan said one of the reasons Walters agreed to speak with the news magazine is his disdain for Wall Street.
The Journal said that Walters, "is a legendary sports bettor." CNBC's Jane Wells said Walters is "unanimously" known as the best sports gambler in Las Vegas.
In the 60 Minutes profile, Walters said he once bought "a lot" of stock in Enron, WorldCom, and Tyco, and said he's met more bad guys "with suits and ties on," than he has gamblers.
The profile also said Walters has been indicted four times.
When Logan asked Walters if the hustler from Vegas got hustled by Wall Street, Walters said: "No doubt about it."
What's The Trade?
Both The Journal and The New York Times reports said regulators are looking into trading in Clorox in the summer of 2011.
In February of 2011, Icahn took a roughly 9% stake in Clorox, and said he believed Clorox's shares were undervalued, "in light of [Clorox's] emphasis on 'mega-trends' and its portfolio's focus on innovative brands that are number one in their respective categories," according to a filing with the SEC.
In the summer of 2011, Icahn made a $76.50 per share offer for Clorox. The Times and The Journal said the investigation is focused on trades in options contracts ahead of that offer.
Both reports also say investigators are examining trades in shares of Dean Foods.
What's The Connection?
The Journal said Icahn and Walters met when Icahn owned the Stratosphere hotel in Las Vegas. Icahn sold the hotel in 2008, and "have talked on occasion since then, including about stocks."
Walters and Mickelson reportedly play golf together, and citing a source, the Journal said Walters has suggested stocks for Mickelson to consider buying.
The New York Times said trading records showed that, "at least one other investor connected to Mr. Walters and the golfing world,"
Icahn and Mickelson have said they don't know each other.
The most recent report from the Journal said the government's investigation has hit a snag following the Journal's earlier report regarding the probe. The report said regulators were weighing the use of wiretaps, among other methods, in their investigation.
The New York Times said that in the case of the Clorox trades, "the authorities initially planned to secure cooperation from one of Mr. Icahn's top employees, the people briefed on the matter said, but shifted gears when they lacked the leverage to do so."
What Now?
This story is not over by a long shot, as Mickelson and Icahn are both two of the most prominent figures in sports and business, respectively.
Mickelson now has just one tournament before the U.S. Open, one golf's four "major" championships, scheduled for June 12.
Icahn told CNBC's Scott Wapner on Friday that, he doesn't know of any investigation, he has gotten no subpoena, he has never given inside information to anyone, and that he has heard of Mickelson but has never met him.
You can read The Journal's initial report here, and its follow-up here.