WebMD is going private.

Amid news that KKR is buying WebMD Health (WBMD) , TheStreet's Action Alerts PLUS Portfolio Manager Jim Cramer said the health website is an "under-monetized asset.

It's also an asset that has been in focus of late. 

The deal represents a big win for an activist investor who cut his teeth working for the private-equity behemoth that acquired the health care web portal.

The sale comes after activist fund Blue Harbour Group LP's Clifton Robbins began building a stake in WebMD shortly after the health care internet portal announced on Feb. 15 that it was conducting a strategic review.

Blue Harbour's Clifton Robbins and his team engage in a collaborative behind-the-scenes form of activism. That means they won't launch a director-election proxy contest to drive a sale. However, the activist fund typically engages the management and boards of companies that are on the receiving end of their large minority investments. They will on occasion push for M&A related efforts to drive share-price improvement in behind-the-scenes negotiations.

It is very likely that they had sought a deal in private negotiations. Consider that Robbins has lots of connections with the buyer, KKR, in part because he worked at the private equity behemoth as a general partner between 1987 and 2000.

In addition, the sale is a big win for Blue Harbour. The fund accumulated its 9% stake between Feb. 23 and March 3 at prices ranging from $51.93 a share and $52.36 a share, significantly below KKR's $66.50 a share acquisition price.

Further, it was a serious possibility that had WebMD not completed a sale of its business that another activist fund, this one more aggressive, could have launched an insurgency at the company.

Jana Partners' Barry Rosenstein recently reported owning a 1.2% WebMD stake. The insurgent fund just last week had liquidated its activist position in Whole Foods with an approximate $320 million profit. Jana Partners is likely looking to invest some of its profits into a new activist target. It was very possible that Rosenstein could have accumulated a significantly larger position and launched a director-election contest to have the company sold or broken into two businesses if it had not taken M&A related steps on its own.

More of What's Trending on TheStreet:

More from Stocks

How to Start Investing at Any Age

How to Start Investing at Any Age

There Is No 'Smoking Gun' With Blue Apron

There Is No 'Smoking Gun' With Blue Apron

Trading in the Age of Computer Algorithms

Trading in the Age of Computer Algorithms

What the Government Shutdown Means for Retail

What the Government Shutdown Means for Retail

Jim Cramer's Take on Netflix Earnings (and the Other FAANG Stocks)

Jim Cramer's Take on Netflix Earnings (and the Other FAANG Stocks)