Got a Bonus or Windfall? Check the Portfolio You’re Adding To
New money is the cheapest chance you will get to fix a lopsided portfolio. Here is what to check before you invest a bonus or windfall, with a worked example of rebalancing without selling.
Key takeaways
- Check your current weights against your targets first, then point the new money at what is underweight. Illustrative: $50,000 sent to bonds moves a 75/25 portfolio of $300,000 to about 64/36 without selling anything.
- Rebalancing with new cash avoids selling winners, so in a taxable account it usually avoids realizing gains.
- Investing at once has usually beaten spreading it out: lump sum beat 12 monthly purchases in 84.8% of 112 rolling windows in Exent’s S&P 500 data.
- Re-run the crash check after the addition. A bigger portfolio means a bigger dollar loss in the same crash.
- How do I check my portfolio before adding a windfall?
- What should I check before investing new money?
- How do I rebalance with new cash instead of selling?
- What would a crash cost after I add the money?
- Should I invest a windfall all at once or over time?
- Common mistakes with a bonus or windfall
- How do I get a second look before investing it?
How do I check my portfolio before adding a windfall?
Look at the portfolio as it is today, decide what it should look like after the money goes in, and let the new cash close the gap. Most portfolios drift: winners grow, losers shrink, and the mix ends up riskier than planned. A bonus, an inheritance or a home sale gives you a way to rebalance without selling a single share.
Two questions come first, before any investing: is any of this money needed in the next few years, and is there high-interest debt to clear? Money with a near deadline usually belongs in cash or short-term bonds. See how much cash to hold.
What should I check before investing new money?
- Current weights: stocks, bonds and cash as percentages of the total, across every account.
- Targets: the mix you want after the addition, written down.
- Largest positions: any single stock above roughly a tenth of the new total.
- Overlap: whether the fund you plan to buy holds what you already own.
- Crash loss: a 2008 replay on the portfolio after the money goes in, in dollars.
- Taxes: which account the money goes into, and whether selling anything would realize gains.
- Timing: all at once, or in steps over a set period with the dates written down.
How do I rebalance with new cash instead of selling?
Send the new money to whatever is below target. Illustrative: a $300,000 portfolio has drifted to 75% stocks and 25% bonds against a 60/40 target. A $50,000 bonus arrives.
| Stocks | Bonds | Total | Mix | |
|---|---|---|---|---|
| Today | $225,000 | $75,000 | $300,000 | 75 / 25 |
| Bonus into stocks | $275,000 | $75,000 | $350,000 | 79 / 21 |
| Bonus into bonds | $225,000 | $125,000 | $350,000 | 64 / 36 |
| Target at $350,000 | $210,000 | $140,000 | $350,000 | 60 / 40 |
- Today
- Stocks
- $225,000
- Bonds
- $75,000
- Total
- $300,000
- Mix
- 75 / 25
- Bonus into stocks
- Stocks
- $275,000
- Bonds
- $75,000
- Total
- $350,000
- Mix
- 79 / 21
- Bonus into bonds
- Stocks
- $225,000
- Bonds
- $125,000
- Total
- $350,000
- Mix
- 64 / 36
- Target at $350,000
- Stocks
- $210,000
- Bonds
- $140,000
- Total
- $350,000
- Mix
- 60 / 40
The bonus alone does not reach the target, but it gets most of the way without a sale. The rest can come from future contributions or a small trim. More in how to rebalance and how to reduce risk without selling.
What would a crash cost after I add the money?
Run the numbers for each choice. The table applies the 2007–09 peak-to-trough declines from our data, as of Sep 30, 2026, to each part: −56.5% for the S&P 500 (SPY) and −14.6% for US bonds (AGG). Illustrative; the two lows did not happen on the same day, so this overstates slightly.
| Portfolio | Value | 2008-style loss | As % of total |
|---|---|---|---|
| Today, 75 / 25 | $300,000 | −$138,000 | −46.0% |
| Bonus into stocks, 79 / 21 | $350,000 | −$166,200 | −47.5% |
| Bonus into bonds, 64 / 36 | $350,000 | −$145,300 | −41.5% |
Should I invest a windfall all at once or over time?
Historically, all at once usually came out ahead. In Exent’s data, a lump sum in the S&P 500 beat the same money spread over 12 monthly purchases in 84.8% of 112 rolling 12-month windows from 2016 to 2026, by 7.43% of the amount on average. Markets rose more often than they fell. Spreading it out reduces the regret of investing just before a drop, and some people need that to stay invested. If you stage it, fix the dates in advance. See lump sum vs dollar-cost averaging.
Common mistakes with a bonus or windfall
- Adding to what is already biggest. In 144 portfolios analyzed on Exent, the median largest holding was already 25.9%. New money is a chance to dilute it.
- Buying what everyone owns. Nvidia appeared in 30.5% of those portfolios. Popular is not the same as underweight.
- Parking it in cash with no plan. Waiting for a better entry often turns into years.
- One big single-stock bet. Size it by what you could lose; see position sizing.
How do I get a second look before investing it?
Check the portfolio you have before you add to it: current weights, concentration, correlation between holdings and crash exposure. Writing down the planned version and comparing the two shows what the new money actually changes. Large windfalls often raise tax and estate questions; a fee-only financial planner or tax professional can help with those.
How to check before you add with Exent
- Upload a screenshot of your holdings, or a CSV, Excel, PDF or Google Sheet; no brokerage login.
- Exent shows current weights, concentration, correlation clusters and crash replays.
- Add the planned purchases in the what‑if simulator to compare the portfolio before and after.
- Multiple portfolios are supported, so you can keep the planned version next to the current one.
Frequently asked questions
Set aside anything needed in the next few years, clear high-interest debt, then compare your current mix with your target and direct the bonus to what is underweight.
Yes. Put new contributions into the parts of the portfolio that are below target. It is slower than selling but usually avoids realizing gains in a taxable account.
Historically a lump sum usually ended ahead. In Exent’s S&P 500 data, it beat 12 monthly purchases in 84.8% of rolling 12-month windows from 2016 to 2026. Averaging in can still help people who would otherwise not invest at all.
Check its weight first. If it is already a large share of the portfolio, adding more raises concentration, and the result depends even more on one company.
It depends on your target mix, timeline and other savings. Work out the mix you want after the addition and how much a 2008-style drop would cost in dollars.
See what your portfolio is really made of.
Upload a screenshot of your holdings and get concentration, overlap, crash exposure and a risk-matched benchmark in about a minute.
Educational content, not investment advice. Examples are illustrative; past performance does not guarantee future results.