A portfolio is the full set of investments you hold: shares, bonds, ETFs, funds, crypto, and depending on how you count, property and cash. The word refers not to the individual positions but to what they add up to.
Two people can hold exactly the same twenty names and end up with completely different results. The difference is in the weighting.
Weight is what it comes down to
weight = position value / total value of the portfolio
This is the column that turns a list of holdings into a picture of concentration. A portfolio can look diversified as a list of twenty names while one of them carries 60% of the money.
Weight drifts on its own
You do not have to trade for weights to change. A position that rises faster than the rest grows its own weight, which is how portfolios quietly become concentrated in whatever has done best. Not a decision, but the absence of one.
What goes wrong
- Count is not spread. Twenty names in the same sector move largely together. See diversification.
- Weight follows your filter. Filter to one sector and weights recalculate within it, summing to 100% again. A weight read under a filter is not the same number as that position's weight in the whole portfolio.
- Investments are not net worth. A neatly spread securities portfolio can sit alongside a home and a business stake, leaving you heavily concentrated overall.
In practice
Gylder shows weight per position, and the diversification donut on the Overview tab is built from the same figures across the dimension you choose. Click a slice and everything filters to it.
Gylder does not recommend a target weight, flag a position as overweight, or suggest rebalancing. Those depend on your horizon, your tax position and the rest of your net worth, and a threshold applied without knowing any of that would be advice dressed up as a calculation.
The Analysis section separately surfaces concentration across your whole net worth rather than within investments, which is a different question and a useful complement.
Related terms
- Diversification: why spread is more than count
- Asset allocation: the split across asset classes
- Volatility: how composition drives movement
Want to keep your split current without recalculating it by hand every month? Read Tracking your investment portfolio without a spreadsheet.