Most portfolio backtesting tools are constrained in ways that matter most: access to limited number of asset classes, short backtesting time span or both.
To address these constraints, PrincetonAsset aggregates data from multiple sources into a portfolio backtesting tool that supports a broad set of asset classes spanning U.S. equities, international markets, fixed income, housing, and real assets, with coverage extending back to 1970.
What This Tool Does Differently
1) Full Asset Class Coverage (Not Just “Total Market”)
Instead of approximating exposures, the tool lets you construct portfolios across the size and value spectrum.
For example, you can explicitly allocate to:
- Total market
- Large value vs growth
- Mid-cap blend/value/growth
- Small-cap and small-cap value
- Micro-cap and ultra-small segments
This allows you to test factor-driven portfolios instead of just broad proxies.
2) Deep International Granularity
Most tools stop at “ex-US.” ours one goes further:
- Developed vs emerging markets
- International small-cap
- International small-cap value
- Region and country specific breakdowns (Europe, UK, Japan, Pacific)
This allows you to model broadly diversified portfolios closer to academic or style factor constructions.
3) Multi-Asset Support
Portfolios aren’t limited to equities. You can include:
- Treasuries across durations
- TIPS (inflation-protected bonds)
- Corporate bonds
- REITs
- US House Price Index
- Commodities, gold and silver
You can also evaluate results in both nominal and real (inflation-adjusted) terms.
4) Long-Term Historical Coverage
Data back to 1970 enables testing across:
- High inflation regimes (1970s)
- Disinflation and rate declines (1980s–2010s)
- Multiple equity cycles and crashes
This is critical for understanding how strategies behave outside recent market conditions.
What You Can Actually Test
Because the tool operates at the asset-class level, you can isolate variables instead of guessing and answer concrete portfolio questions:
- How much small-cap value exposure is optimal?
- Does international diversification improve risk-adjusted returns?
- How does a 100% equity portfolio compare to a mixed allocation?
- What drawdowns should you realistically expect?
- What withdrawal rates are sustainable under different allocations?
For the portfolio Real Returns we included ±1/2/3 standard deviation bands to highlight how volatile outcomes can be over time.
Design Philosophy
This tool is built around a few principles:
- Asset-class clarity
- Deterministic backtesting (no black-box assumptions)
- Support for serious portfolio construction
It’s designed for investors who want to understand why a portfolio behaves the way it does not just see an output.
We strongly point out that this tool is not a portfolio generator, it’s a diagnostic tool:
useful for understanding behavior across regimes, not predicting the future…
This tool is designed with that constraint in mind. It’s not trying to tell you: what the “best” portfolio is. It’s trying to help you see: what a given portfolio actually does.
Backtesting is fun
It allows you to understand asset class history and see how they behaved in different regimes.
To test a specific idea: factor tilts, international exposure, or withdrawal behavior, you can build your portfolio backtests directly at: https://go.princetonasset.com/portfolio/new
- edit, save or share
- free with or without an account
Or search for shared models here: https://go.princetonasset.com/
Disclaimer: This blog post is for informational purposes only and should not be considered financial advice. Consult with a qualified financial advisor for personalized guidance.
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