If you hold shares through more than one broker, you may look at each account's sector mix on its own. A sector percentage for one account describes that account alone. It doesn't tell you how much of your money, across all the accounts, sits in one sector.
Three accounts reading 10%, 10% and 100% can come to 28% of the money across them, depending on how big each account is.
Why each account's percentage stands alone
A sector percentage is the sector's value divided by the account's value. Each account divides by a different total, so the percentages are on different scales.
Many investors end up with several accounts: an old one, one opened for lower fees, and a smaller one used for trading. When you check them one at a time, you build a picture in your head. The larger accounts look spread out. The small account looks too small to matter. A dollar of tech counts the same in every account, so that picture can be well off.
Worked example: three accounts, one sector
This example is hypothetical. Every amount is in the same currency, every holding is owned shares (no short positions), and each account's value includes its cash.
| Account | Account value | Tech share of the account | Tech in dollars |
|---|---|---|---|
| Account 1 | $40,000 | 10% | $4,000 |
| Account 2 | $40,000 | 10% | $4,000 |
| Account 3 (smaller, traded more often) | $20,000 | 100% | $20,000 |
| All three | $100,000 | 28% | $28,000 |
The smaller account holds a fifth of the money, so it's easy to overlook. Because it's all tech, it supplies most of the tech total.
Combined: $28,000 of $100,000 is 28%, more than one dollar in every four.
Two shortcuts that give the wrong answer
| Shortcut | Result | Why it's wrong |
|---|---|---|
| Go by the two big accounts | about 10% | It leaves out the account that holds most of the tech |
| Average the three percentages | 40% | It treats a $20,000 account as if it were the same size as a $40,000 one |
Adding account percentages doesn't give a combined share, and a simple average ignores account sizes. The combined figure is the sector's dollars across every account, divided by the dollars in every account.
A larger share is not a verdict
28% in one sector is not good or bad on its own terms. The example only shows that the figure you'd form from separate account screens can differ from the combined figure. Knowing the combined figure lets you decide whether it matches what you intended.
For a related case, where an index fund and your own picks double up on the same companies, see portfolio concentration.
Seeing the combined figure in Swingfolio
In Swingfolio, you keep each broker account as its own portfolio. On the Trades page, in the open positions view, the Holdings index card shows your holdings as one line, with a portfolio selector when more than one portfolio holds open positions. With All portfolios selected, the allocation breakdown beside the line shows:
- By Sector: each sector's share of all your portfolios together
- By Ticker and By Exchange: the same combined view by holding and by exchange
The breakdown combines the open positions the Trades page is showing, converted to your display currency, plus your cash across all portfolios. Clear any Trades filters first so every position is counted. Short positions appear as their own slices, sized by their value. Pick one portfolio instead and you see that account on its own, in its own currency.
Open the Trades page in Swingfolio, clear the filters, select All portfolios and check By Sector before you add to a sector.
Frequently asked questions
Can I just average the percentages if my accounts are similar in size?
A simple average matches the combined figure when the accounts are the same size, or when they all hold the same share of the sector. Otherwise it can be off, because it gives a small account the same weight as a large one. The combined dollars always give the right answer.
Does cash change the answer?
Yes. Cash is part of each account's value, so it is part of the combined total. In the example, each account value already includes its cash. Swingfolio adds cash to the breakdown when the combined cash balance is above zero.
What if my accounts are in different currencies?
The combined figure needs every account in one currency first. Swingfolio converts each position to your display currency before adding them up.
The accounts and amounts above are hypothetical. General information only. Not financial advice.