Brk investors receive a moderate return. The day of significant market beating is past for berkshire, the firm is way too big.
The trick is to strike a balance. Easy said than done. At least 15 to 20 positions in order to manage risk effectively. Then how to weight each position is another art.
It depends, pic the right stock and you're good to go. But usually advisors use it to churn your account because they're poor stock pickers. Plus they're paid by commision. I can name a dozen+ stocks you're better off buying any one of them and hold. Then use options ...
Diversification in the forex field fails when risk tolerance falls (or rises) significantly across the wider financial sector. Look at the Brexit effect for the last 2 months or so. Why would the UK leaving the EU have an impact on USD/JPY, or AUD/CAD? But yet it has.
%% [1]Single stock is too much risk; ask GM, DAL+ Bear Stearns hit the dirt in a bear market.Plus more traders market risk since your JAN, 2009 post; investments that pay dividends may do well. NOT a prediction, not much of a DOW watcher.,
There isn't a number, market risk will always exist for every stock,so i think a proper cash/equity balance is more important. Diversify to the extent that localized sector or company disasters won't tank you.