Jane Ross

Ross is a key advisor to some of the biggest names in tech ? Facebook Inc., Intel Corp., eBay Inc., Paypal Holdings Inc., Adobe Systems Inc. and Dell Inc., among others. She shepherded Intel through its $16.7 billion acquisition of Altera Corp., Intel's biggest acquisition to date and the fifth biggest acquisition overall of 2015.

That was dwarfed by her work on Facebook's $22 billion buy in late 2014 of mobile messaging company WhatsApp, which lets users send text messages nearly free over the Internet. The deal, Facebook's largest acquisition to date, came with its own set of challenges, including the need to get clearance from Chinese antitrust authorities. "The amount of business both companies do in China is significant," Ross said.

China has long blocked Facebook and the WhatsApp purchase was widely seen as a bid to crack that enormous market. "What is peculiar is that the Chinese process is very unpredictable, both in speed and outcome."

Beyond the size of the deal and its international implications, though, Ross said it was essentially indistinguishable from other public company transactions she has managed. "Such deals are going to be filed publicly to get shareholder approval, so although they tend to be high-stakes and important to the companies involved, since the details are known there are a narrower number of things to be negotiated."

Because as much as 95 percent of public company deals are subject to shareholder litigation, companies are unwilling to go beyond accepted norms under Delaware law, where most companies are registered, Ross said. That tends to eliminate potentially provocative terms like protections for the buyer. She's become an expert in legal developments in the state. "I'm not a litigator, so I don't actually go to Delaware," she said. "But you can't be a M&A attorney without keeping up with changes in their law. I probably know more Delaware law than California law."

The WhatsApp purchase happened fast, Ross said. "You move quickly to prevent leaks. We got the call on Valentines Day Friday and signed the next Wednesday. They made the decision, we got our marching orders and we executed." Private deals can take longer because there's no fear that leaks can move stock prices. To speed the deal, she said, the lawyers all went over to Fenwick & West LLP's Mountain View offices to deal directly with the lawyers representing WhatsApp. "We lived in their conference room," she said. "There was a lot of food brought in, around the clock. There wasn't a lot of room for sleeping."

John Roemer