William Finnegan IV, a partner in Latham & Watkins’ Houston office, is a pioneer in the energy industry, known for shepherding high-profile, high-stakes transactions for some of the largest energy companies in the world, with a focus on midstream master limited partnerships (MLPs). For example, Finnegan has advised on all of Texas-based Energy Transfer’s securities work and most of their M&A transactions over the last decade, including the company’s $5.3 billion acquisition of Sunoco, its $7.9 billion acquisition of the Southern Union Company and its $18 billion acquisition of Regency Energy Partners, which at the time, made Energy Transfer the second-largest MLP in the world. And he hasn’t slowed down a bit. In 2018 alone, Finnegan guided dozens of energy deals valued at more than $199 billion.

The legal profession is constantly evolving and that evolution only seems to have accelerated in recent years. What’s the biggest change you’ve seen in the profession during your career?