Investors Who Concentrate
Diversification protects capital; concentration builds it. The investors in this collection sized their best ideas at levels most risk committees would veto — and their track records are the strongest argument in the sizing debate.
Read them together and a shared discipline emerges: extreme selectivity, long holding periods, and the willingness to look wrong for years.
Warren Buffett
Put roughly 40% of the early partnership into American Express during the salad-oil scandal — the template for betting big when the odds are obvious.
Read the full Warren Buffett breakdownCharlie Munger
Argued three great businesses are enough for a lifetime; his own fund held a handful of positions with brutal drawdowns and superior compounding.
Read the full Charlie Munger breakdownGeorge Soros
Broke the Bank of England with a $10 billion position — the canonical example of sizing up when conviction and asymmetry align.
Read the full George Soros breakdownJohn Malone
Concentrated everything in cable, then levered it — using debt and tax structure rather than diversification to compound TCI shareholders' capital.
Read the full John Malone breakdownHenry Singleton
Bought back 90% of Teledyne's shares when they were cheap — concentrating remaining shareholders into the best asset he knew: his own company.
Read the full Henry Singleton breakdownMark Leonard
Constellation Software never diversified away from vertical-market software; Leonard concentrated on one repeatable acquisition playbook for 30 years.
Read the full Mark Leonard breakdown