Chris always writes one of my favorite letters, and one of the few must-reads for me every year. And he's outdone himself this year. This is great to read in tandem with Warren Buffett's annual letter, which will be released in the morning.
Link to 2018 SAI Letter: Addicted to Loans: A Bubble In Debt, The Trouble With Earnings, The Second Great Pivot At Berkshire Plus: The ROE You Will Not See!
And if you want to review all of Chris' deep dives into Berkshire, I recommend his 2015 letter, followed by his 2016 interview with Kate Welling, then the 2016 letter, 2017 letter, and 2018 letter.