Keep that in mind as you come across recent arguments to the contrary. It’s always tempting to believe you can beat the market in your 401s, IRAs, and other retirement portfolios. But this temptation becomes irresistible when—as a recent report suggests—well more than half of actively managed funds and ETFs are beating their benchmarks.
The true picture is a lot less rosy than what this recent report suggests, however. That’s not because Morningstar’s calculations aren’t accurate. But if one group of active managers is beating the market, then it must be the case that another group is lagging. And once transaction costs are taken into account, the average market-weighted return of all active managers must—of necessity—be below the return of the market as a whole.
Sharpe’s arithmetic-based argument does allow for this or that individual manager beating the market, especially over the short term. But for every active manager who comes out ahead, of necessity another active manager must be lagging the market. That’s because beating the market is a zero-sum game before transaction costs, and a negative-sum game after transaction costs.
His advice was to create two separate portfolios—one Permanent and one Speculative. The former would contain the bulk of your assets and would be invested in index funds and held for the long term with little or no change. The Speculative portfolio would contain your play money in which you try your hardest to beat the market.