Using the Big Picture app


  1. A rolling period is a fixed period of time that shifts from one start and end date to the next start and end date for which values are available. The start date for each rolling period always precedes the end date of the previous one. In this way, rolling periods are partially overlapping.

    • Example 1. With data of monthly frequency, there are 13 one-year rolling periods over any two years. The first is from January 1 to December 31 of the first year. The second is from February 1 of the first year to January 31 of the next. And so on.
    • Example 2. There are over 845 twenty-year rolling periods between 19261935 and the present. The first is from January 1, 19261935 to December 31, 1945. The second is from February 1, 19261935 to January 31, 1946. And so on.

  2. If you wish to go offline and continue using the app, you must NOT exit the application. If you logout, refresh your browser, close your browser, or clear your browser's cache, you will exit the application and will not be able to access it while offline. The Big Picture app will only function offline while your subscription is valid. You need an internet connection the first time you access the Big Picture app, and to receive periodic software updates and monthly data updates.


  3. When the "Adjust for Inflation" is ON, the app performs all calculations in real (i.e. inflation-adjusted) terms. Inflation is netted out of historical investment performance, and monthly portfolio contributions and withdrawals are assumed not to grow at the rate inflation that prevailed each month of each rolling period contemplated. This is the default setting.


    When the switch is OFF, the app performs all calculations in nominal terms, and monthly portfolio contributions and withdrawals are grown at the rate of inflation that prevailed in each month of each rolling period contemplated.


  4. When the app returns a value preceded by a < or > symbol, it means the answer lies outside the range of values that is feasible for the app to calculate or display.


    The app backtests rolling investment periods ranging from one to forty years in duration. It cannot backtest periods that are shorter than one year, or longer than forty years.


  5. Tax rates have varied significantly through time, by jurisdiction, and according to the legal and financial circumstances of particular individuals. They are therefore excluded from the app's calculations. You can adjust the "MER" slider to gauge the impact of expenses on investment results.


  6. The app considers withdrawal rates as percentages of starting capital. The annual dollar equivalent is calculated, and then divided by twelve. The resulting amount is then adjusted by the actual rate of inflation that prevailed in each month of history (if the "Adjust for Inflation" switch is set to OFF), and is withdrawn monthly from the portfolio balance. Withdrawals are not adjusted based on portfolio performance.


  7. To avoid double counting, you are advised to exclude the value of a paid-off house from the app (and consider it perhaps as an emergency source of funds). The reason is that one's paid-off house is already considered by the app to the extent that it reduces one's monthly spending (or increases one's savings rate, as the case may be) through foregone mortgage costs. If a house were to be sold or mortgaged, new expenses for rent or debt payments would be incurred.


  8. Yes. The Big Picture app is a web-based app. However, please note that the user experience is currently optimized for computer displays and medium to large tablet devices. The current minimum screen width for tablets that does not necessitate horizontal scrolling is 1024 pixels.


    A smartphone-compatible version is currently under development. Sign up here for a free Big Picture Basic account to receive product updates.



  9. Yes, the app works across major browsers. However, on Mac, it performs ideally on Safari. On PCs, it works best on Google Chrome. The minimum supported version of Internet Explorer is 10.


  10. You may access the app on up to three devices. We track usage and will close sessions that are running concurrently. See our Terms of Use.


  11. You can "pin" the Big Picture application to your mobile device's home screen in a matter of seconds. The benefits of doing this are multiple. The main benefit is that it allows you to launch the app with a single tap, rather than having to open your browser and navigate to the site. Follow this link to learn how to add a shortcut to your specific device.