UG Networking Paying Off Later In Your Career

If you search WSO, you’ll find countless networking tips, guides, what to do, what not to do, how to get me on the phone, when to not network, where to network, ect and ect. However, they mainly focus on either networking to break into the industry, or how to network to jump to the buyside. However, I was wondering if anyone had stories or tips to how to network with the goal of doing both: connecting with current bankers who are jumping to the buyside who can help you break in and then move to the buyside, or with current buyside guys who recently made the jump from IB. Also, any good stories that stem from a connection you made as an undergrad like starting a company, or something of the sort? Looking forward to hearing some stories.