Historical investing tools, reproducible studies, and practical reading guides
Historical investing tools, reproducible studies, and practical reading guides
Sun Insight Lab
Free browser tools for testing investing ideas on real market history — no sign-up, no advice, just numbers you can check yourself.
Sun Insight Lab is a free, independent resource for everyday investors — part toolkit, part plain-English commentary. The browser-based tools let you test investing ideas against real historical data, from a single stock to a full strategy across the S&P 500, while our market analysis helps make sense of what's actually moving prices. No sign-up, no advice — just a clear place to see how investing decisions play out over time.
Educational backtest using current S&P membership and share counts applied backward. These approximations can materially bias every factor. Stored adjusted equities differ from the price-only index benchmark. Taxes, fees, and slippage are excluded. See methodology.
The toolkit
Six free tools, all built on the same checkable price history.
Test a lump sum plus a monthly amount in one stock, an index, or a basket. Line up to five tickers side by side and flip rebalancing on or off.
Sort the whole index by one trait — size, momentum, steadiness, value, or quality — hold the top names equally, and rebalance on a set schedule against the index.
Run long-haul contributions, including TSP and 401(k)-style accounts, and see how steady saving plus compounding shape the final balance.
A gauge for how narrow the S&P 500 rally has gotten — built on the old dot-com lesson that breadth fades before a top.
Notes on what's really moving the market — deep dives, trend pieces, chart basics — each tied to a scenario you can replay in the simulator.
Twenty no-jargon guides on risk, valuation, diversification, earnings, dividends, and the habits that matter more than picking the perfect ticker.
How it works
The Quant Lab runs one simple experiment, over and over. Each rebalance it sorts every company in the S&P 500 by a single number, buys the top few (3, 5, or 10) in equal amounts, holds them, then re-sorts and trades again on a set schedule — monthly, quarterly, twice a year, or once a year. It puts your starting cash and monthly contributions to work the same way the simulator does, then draws the result against the S&P 500 doing the same thing. Hover over any month to see exactly what it was holding.
You pick which number it sorts by — five styles most traders know:
Current membership, current share counts, limited fundamentals, and transaction-cost omissions can materially change historical rankings and results. The tool does not reconstruct a fully investable historical universe. Use it to examine stated rules, and read the data limitations alongside the factor-specific help.
Analysis
A discount-rate worksheet and a way to distinguish observed prices from explanations of a selloff.
Reading guideSix things every investor should know how to read on a stock chart — candlesticks, support and resistance, trend types, moving averages, and the three patterns that most reliably signal a new uptrend.
Reading guideSeparate reserve balances, reserve income, distribution costs, and shareholder profit before interpreting stablecoin growth.
Reading guideReview business evidence, concentration, and cash needs with a hypothetical position-size calculation.
Reading guideA worked concentration example and an honest guide to the Bubble Meter’s historical limitations.
Reading guideA hypothetical utilization and rental-rate model that separates customer demand from financing and profit.
Reading guideVerified issuer figures and a worked explanation of why one quarter cannot establish a stock’s fair value.
Reading guideWhat an ETF actually is, why asset managers keep launching new ones, the four numbers worth checking before you buy (net assets, expense ratio, volume, distributions), and why leveraged and inverse ETFs lose money in ways their charts don't show.
Reading guideWhat the August 2026 announcement establishes, what remains conditional, and a hypothetical lending stress test.
Reading guideEverything a beginner needs from a financial statement fits into nine plain-English words: revenue, operating income, net income, assets, liabilities, equity, ROE, moat, and earnings growth. Here is what each one answers.
Reading guideA share-count reconciliation worksheet explaining why position value changes do not reveal purchase spending or investor intent.
FAQ
The public tools are free and do not require an account. Calculations run in your browser, while market-data requests go to our API. The separate private portfolio plan uses a PIN login; see Privacy.
It's a rule that sorts every stock in the S&P 500 by one trait — size, recent gain, steadiness, cheapness, or profitability — buys the top names in equal amounts, and rebalances on a fixed schedule. It shows how that kind of discipline would have done versus just holding the index.
Current S&P membership and current share counts are applied backward. This can materially affect all factors, including market cap and momentum. Historical winners are selected with information unavailable at the time. Treat the results as educational approximations; see methodology.
No. This is for learning, full stop. A backtest only tells you what a rule did in the past, and the past doesn't repay the future. Nothing here is a recommendation to buy or sell anything.