In-house counsel Susan Jackson recalls when she was handed the North American trade portfolio at Novelis Corp. about five years ago, she wasn’t all that thrilled. She even thought it might be boring.

She found just the opposite. “It’s dynamic and very exciting,” Jackson told Corporate Counsel in a recent interview. “Things can change in a moment from one tweet.” For example, President Donald Trump can and has sent the stock market tumbling with a tweet threatening to levy more tariffs on imported goods.