The most influential name in activism you've never heard of is on an absolute tear

There is a big name in activist investing that has been involved in more than 50 campaigns so far this year.

It isn’t Pershing Square, Icahn Associates, or Third Point. You have probably never heard of it.

It is Wall Street law firm Olshan Frome Wolosky LLP.

The firm is the the go-too legal adviser for many of Wall Street’s biggest and most successful activists.

It has worked for clients include Jeffrey Smith’s Starboard Value LP, along with Lone Star Value Management and Glenn Welling’s Engaged Capital LLC.

The more than 50 activist campaigns the law firm advised on so far in 2015 is equivalent to 22% of the all campaigns, according to FactSet data.

That puts Olshan ahead of the next seven law firms by market share — combined.

The law firm’s activity in activism appears to be growing as the strategy is becoming increasingly popular with investors.

Steven Wolosky, a partner and chair of the activist and equity investment practice at Olshan, told Business Insider that most of his clients are focused on operational activism, rather than turning a quick buck.

Activists are now acting almost like private equity firms, performing diligence on a deal and looking to market their viewpoints to institutional investors, he said.

“It’s beyond the performance of the company,” said Wolosky. “It’s beyond the CEOs performance.”

The rise in activism has placed a premium on legal expertise. Hedge funds and big banks alike are eager to bring experts into their ranks to ready defences in increasingly costly campaigns to control boards’ independence.

Ex-activist lawyer David Rosewater was recently hired to head Morgan Stanley’s activism defence practice; another ex-lawyer teamed up with a former JPMorgan executive to launch an activist fund focused on collaborative management earlier this year.

And Bill Ackman’s Pershing Square Capital fund hired ex-Kirkland & Ellis lawyer Stephen Fraidin in January after the M&A pro spent more than a decade on the hedge fund’s advisory board.

Olshan’s dominance comes at a crucial time for activist investing. There is more cash than ever being put to workin the strategy.

Activist demands bar chart lighter 2015Data from Activist InsightActivist investing has been on the rise, and it is good news to Wall Street banks.

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