A former Bristol-Myers executive is facing hefty fines and decades behind bars for insider trading.

Robert Ramnarine, who worked for the company in various senior roles, admitted that he bought stock in Amylin Pharmaceuticals Inc. because he knew his employer was about to acquire the biotech company for $5.3 billion.

In August 2012, federal prosecutors had charged Ramnarine with three counts of  securities fraud, claiming he illegally made more than $300,000 from his investment in Amylin, as well as two other pharmaceutical companies Bristol-Myers was set to buy. The company fired Ramnarine that same month.

According to prosecutors, Ramnarine became aware of the takeovers while he was working as a director and executive director in Bristol-Myers’ pension and savings investment office. He then began to research insider trading on the Internet, reading an article called “Ways to Avoid Insider Trading.”

Although Ramnarine agreed to forfeit his earnings from the illegal trades, he still faces 20 years in prison and a $5 million fine.

Read more recent insider trading stories and columns on InsideCounsel:

Former KPMG partner pleads guilty to insider trading

SEC reaches final settlements in “Golden Goose” case

Ex-Enron CEO reaches agreement with DOJ to reduce prison sentence

Litigation: Insider trading—let the tippee beware