Mayer revives and extends Robert Kirby's 1984 concept of the "coffee can portfolio" — named after the old practice of putting important documents in a tin can and burying it — to make a behavioral argument as much as an investment one. The concept is simple: select a set of high-quality businesses and then deliberately make it difficult to sell them.

The empirical evidence Mayer marshals is striking. Studies of actual brokerage account performance consistently find that accounts with the least trading activity outperform those with the most. The difference is not usually stock-picking skill; it is the elimination of the transaction, tax, and behavioral costs that active trading imposes. Every time an investor sells a 100-bagger in the making at a 3× or 5× gain to "take profits," they are cutting off a compounding curve that would have delivered much more.

The coffee can approach is psychologically difficult because it requires tolerating large paper losses during market downturns without selling, resisting the temptation to "upgrade" to a newer story, and sitting still while friends brag about recent trades. Markets provide constant stimulation and new narrative. Doing nothing feels irresponsible even when it is optimal.

Mayer's deeper point is structural: the investment industry profits from activity, not from inactivity. The incentive system pushes against the coffee can approach at every level — advisor fees, media cycles, analyst upgrades. The individual investor's edge is precisely the freedom to ignore all of that and hold.

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