Data Guide

Most people do not only want a number. They want to know whether they can trust that number. This guide exists to answer exactly that question.

When you compare scenarios in a calculator, small differences in data or assumptions can create big differences in long term outcomes. Understanding the data layer helps you avoid false confidence.

We separate historical information from user assumptions so you can clearly see which part of your result comes from real past market behavior and which part comes from your own future settings.

This page is written for practical decision support. You do not need to read code or technical files to understand how the platform works.

If you are planning monthly investing, comparing metals versus crypto, checking S&P 500 scenarios, or translating money across inflation periods, this guide helps you read outputs in the right context.

For crypto, metals, and S&P 500 mode, we use monthly market history from Yahoo Finance as the source for historical price levels.

For inflation, we use official public statistics instead of market data: US CPI from the U.S. Bureau of Labor Statistics (BLS) and UK CPI from the UK Office for National Statistics (ONS).

BLS describes CPI-U as a monthly measure of average price change for a market basket paid by urban consumers. ONS describes CPI as a consumer basket that is reviewed regularly to stay representative.

S&P 500 mode is based on index history for ^GSPC, a widely used broad benchmark for large US equities.

No single data source is perfect in every context, so we focus on transparent handling, consistent monthly processing, and clear limits rather than pretending uncertainty does not exist.

The end goal is simple: give you a stable and understandable base for scenario planning, not investment hype or black-box outputs.

Each month, we run an automatic synchronization cycle to refresh supported crypto, metals, S&P 500, and inflation datasets.

After new monthly data is collected, we validate structure and continuity before publication. This helps prevent broken or incomplete updates from reaching users.

If a source is late, unstable, or temporarily inconsistent, we prefer to hold publication instead of pushing uncertain updates.

This means your calculations are based on a dataset that is both recent and quality checked, not just quickly fetched.

In practice, you may see small result shifts from one month to the next because one extra historical month can slightly change compounding paths.

Your own assumptions still matter most for long horizons, but regular monthly refreshes keep the historical part current and relevant.

For crypto, metals, and S&P 500 mode, the calculator moves through time month by month. It applies monthly market change to your running balance and adds contributions according to your settings.

Contribution frequency is normalized so weekly, monthly, or yearly plans can still be compared on one timeline in a fair way.

When a selected horizon goes beyond the last available real market month, the projection continues with your own assumed annual return for the forward part.

Inflation mode is intentionally different. It uses CPI index ratios between years to translate purchasing power, rather than simulating market returns.

Date ranges are bounded to available official CPI years. This avoids inventing synthetic future inflation values that are not present in the source data.

So the platform combines two layers: historical data replay where data exists, and transparent user assumptions where history ends.

A monthly update is not only a data import. It also includes checks to confirm that data is still usable for stable scenario calculations.

We check for issues such as malformed values, timeline inconsistencies, missing segments, and suspicious jumps that could signal a source problem.

We also monitor whether calculator outputs still behave as expected around edge cases, such as boundaries near the last historical datapoint.

If checks fail, publication is paused and reviewed. We only publish after the dataset passes validation.

This process is designed to protect end users from silent regressions that could otherwise produce misleading projections.

In other words, we prefer delayed accuracy over fast but unreliable updates.

Automatic checks: format integrity, ordering, and continuity of historical ranges

Behavior checks: edge cases around range limits and transition to assumption-based projection

Release rule: publish only when validation passes

Historical performance is informative, but it is never a guarantee of future outcomes. Treat results as scenario guidance, not certainty.

Forward projections are highly sensitive to your assumptions. A small change in assumed annual return can produce a large difference over many years.

Real life costs are personal and platform specific. Taxes, custody costs, product spreads, slippage, and behavioral timing decisions are not universally modeled in one single default output.

The S&P 500 series used here is an index-level price history input. It should not be interpreted as a complete personalized portfolio return forecast.

Inflation comparison shows purchasing power translation based on official CPI series, which is useful context but still not a full personal cost-of-living model for every household.

For better decisions, compare conservative, base, and optimistic scenarios instead of trusting one headline number.

Use ranges: always compare multiple assumptions

Read phases separately: historical replay and assumption-driven extension are different phases

Stay realistic: include costs and uncertainty in your interpretation

The crypto calculator uses monthly historical close levels for each supported coin pair and derives month-to-month returns from those levels.

Your contributions are converted into a monthly equivalent so different contribution rhythms can be compared consistently.

Each coin has its own earliest available year. Older assets usually provide longer historical windows, while newer assets naturally start later.

If a month is missing inside historical coverage, the model avoids inventing a synthetic jump for that month and keeps the process stable until the next valid datapoint.

When your selected timeline extends beyond the last real month available, the projection continues using your own annual return assumption.

Display currency helps readability in the interface. It does not rewrite the underlying historical path for the asset itself.

This setup is useful for comparing recurring investment scenarios in volatile markets while keeping data handling transparent.

Supported assets: major crypto assets available in the calculator selection

Core logic: monthly historical replay plus recurring contribution compounding

After data end: user-defined return assumption drives forward projection

The metals calculator follows the same monthly replay concept as crypto mode, but applies it to major metal market series.

Monthly changes are applied over time and your contribution plan is normalized so that contribution frequency remains comparable.

As with other investment modes, if your period runs past the latest historical datapoint, your assumption is used for the forward segment.

This data is a market proxy and is useful for scenario comparison. It is not a full physical ownership model.

Practical real-world factors such as storage, insurance, dealer premiums, and specific product spreads can differ from user to user and are not universally embedded in one default line.

History depth can vary by metal, so available start years and scenario length flexibility may differ between gold, silver, copper, platinum, palladium, and aluminum.

Used correctly, this tool helps you compare contribution discipline across different metals in a consistent framework.

Typical assets: gold, silver, copper, platinum, palladium, aluminum

Main use case: long-term recurring strategy comparison between metals

Important context: market benchmark behavior, not full physical holding cost simulation

The S&P 500 mode on the homepage uses monthly index history for ^GSPC and applies those month-to-month changes to your contribution plan.

S&P 500 is widely used as a broad benchmark for large US equities, so it is useful as a reference scenario for long term investing discussions.

To keep timeline calculations stable, missing months in the raw sequence are handled in a consistent way so that scenario outputs remain comparable.

You can optionally include transaction cost per contribution and TER drag, which helps approximate investing friction instead of assuming a cost-free world.

When selected years move beyond historical coverage, your own assumed annual return is used for the forward period.

Interpret this as an index-based planning model. It supports comparison and expectation setting, but it is not a promise of your personal future portfolio path.

Best for: testing disciplined recurring investment scenarios against broad index history

Optional realism: transaction costs and TER impact can be included

Forward extension: driven by your own assumptions after historical range

Inflation mode uses official CPI series from public institutions: BLS for the United States and ONS for the United Kingdom.

This is intentionally different from market return tools. The inflation calculator is focused on purchasing power translation between years.

It compares CPI index levels between your selected dates and shows what the same amount of money represents in the target year.

For usability and transparency, dates are bounded to available CPI years rather than extended with guessed future inflation values.

This approach gives a conservative result grounded in official published series, which is especially useful when you want to compare nominal money versus real buying power.

If you use this together with investment scenarios, you can better understand the difference between portfolio growth and what that growth may actually buy later.

Source type: official public inflation statistics (CPI)

Main purpose: translate purchasing power across years

Range rule: no extrapolation beyond available official CPI years