International Taxation Question

Lucy Laurel, a U.S. citizen, is the founder of Lollipops Inc. The entity is a Delaware corporation and has been in business for several years. In 2019, Lucy renounced her U.S. citizenship and moved to Bermuda. For the last 10 years, her salary from Lollipops Inc. exceeded $850,000 annually. Her stock in Lollipop Inc., which was her only significant asset, was worth $15 million when she renounced her U.S. citizenship. Her basis in the stock was $10,000. She had no significant liabilities. What are the U.S. tax consequences of Lucy renouncing her citizenship in 2019? Be sure to include relevant Code sections and important definitions in your answer.