High-profile, billion-dollar start-up sales like those of Instagram, Tumblr and Waze have drawn the attention of a wide range of investors, and now some of the world's largest companies want a piece of the action.
Since May, several major names, including Microsoft, General Electric and Bloomberg, have launched venture capital firms. They're trying to profit from start-ups' innovations as well as figure out how to hedge against being disrupted by those innovative technologies.
More than 750 companies worldwide had corporate VC as of last fall, according to a report from Global Corporate Venturing.
And corporate VCs are crucial to the venture industry. In the first quarter, corporate venture investors were involved in almost 17 percent of all deals, contributing 7.8 percent of all venture dollars, according to PricewaterhouseCoopers and the National Venture Capital Association MoneyTree Report.
Citi Ventures Managing Director Vanessa Collela said she's interested only in companies in Citi's wheelhouse that can benefit from its expertise, and give the bank insight into a key area.
"We want it to be strategic for Citi because we think it's a place where we can add value," she said. "We also want it to be strategic for the start-up."
Collela likes to look in unexpected places—such as Detroit—that might not be considered traditional entrepreneurial hotbeds. But when it comes to category, she's focused on payments and cybersecurity.
"We're investors in Square, and [the payment space] has been a big area for us, but there are a lot of areas that are critical," Collela said.
Citi Ventures also has invested in a number of security systems: Pindrop Security, Click Security and Silver Tail Systems, which detects and prevents fraud. In digital payments, it has put money into Linkable Networks, which can provide coupons and offers directly to a credit or debit card.
In contrast, Google Ventures chief Bill Maris said he's not driven by strategic alignment: The start-ups his unit invests in do not need to be potential acquisition targets or helpful to Google in any way. But they do need to be able to benefit from Google's assets.
"We have this giant global corporation that has resources, and we should deploy those resources to help start-ups," Maris said.
Some of Google's recent investments—such as crowd-funding start-up CircleUp and automated home thermostat company Nest Labs—don't have any obvious connection to the search giant. But others seem a more natural fit. The company invested in website optimization platform Optimizely, which could help the many small businesses that use its services. And NextDoor, which it invested in a Series B round in February, could be a good fit with Google Plus circles.
Google Ventures' most overt push for strategic start-ups is a separate fund. It recently started the Glass Collective with Andreessen Horowitz and Kleiner Perkins Caufield & Byers to fund start-ups to create apps and products for Google Glass.
(Read More: 'Naked and Lonely' Without Google Glass: Andreessen)
The exposure his start-ups get to Google's assets is a big win, according to Maris.
"It's the law of unintended consequences," he said. "There have been so many benefits from having 170-plus company founders with access to Googlers and the ability to talk to them and to engineers, and access to resources that they wouldn't have had otherwise. When you start down that path [of access], you learn all kinds of benefits you couldn't predict."
—By CNBC's Julia Boorstin. Follow her on Twitter