Portfolio

Your portfolio is the sum of all your investments – the mix of shares, ETFs, bonds, property, overnight money and other investments.

Why the mix is decisive:

Harry Markowitz proved in 1952 (Nobel Prize 1990): the right allocation (asset allocation) determines over 90% of your return – not the choice of individual shares.

Simple portfolio models:

1. "Slipper portfolio" (Pantoffel-Portfolio, Stiftung Warentest):

• Defensive: 25% equity ETF + 75% overnight money/bonds
• Balanced: 50/50
• Offensive: 75% equity ETF + 25% overnight money

2. Rule of thumb by age:

• Equity share = 100 − your age
• At 30: 70% shares, 30% safe
• At 50: 50/50
• At 65: 35% shares, 65% safe

The problem with German investors:

• Germans hold a median of only 3.5 positions in their portfolio – far too little diversification
• 37% own only 1–2 securities
• Too much "home bias": Germans invest disproportionately in DAX shares instead of worldwide

Rebalancing:

Restore the original allocation once a year. If shares have risen sharply: shift some of the gains into safe investments. This lowers the risk and enforces "buy low, sell high".