A scope for looking back

Hindscope is a free tool. You build a test portfolio and replay it through real stretches of market history, such as 2008, 2020 and 2022, next to the S&P 500. It works on a phone, takes about a minute, and asks for no account.

It has three parts: the tool, a crash rule that runs in public with every past state on record, and a demo dashboard that shows your test portfolio as if it were a real account.

I'm David. I have a technical background and no coding experience. I manage my own investments, and I built my private dashboard, the crash rule and this site with AI tools.

I am not a financial adviser, and nothing here is advice.

David

Market sleeves, such as the S&P 500 or gold, follow the real price history of a large fund that tracks that market, with dividends included. The funds are SPY, QQQ, IWM, EEM, BIL, IEF, LQD, VNQ and GLD.

Strategy sleeves, such as swing trading or covered calls, are estimates. The tool does not backtest them. You enter the yearly return you expect. The tool compares it with the S&P 500's average of 10.6% a year and moves the sleeve that many times as far as the S&P 500 every day, up and down. Expect 1.5 times the average and the sleeve moves 1.5 times as far, so a higher expected return means bigger falls. Choosing "covered calls" or "swing trading" changes the name only. The number you enter does the work.

The portfolio is bought on the first day and left alone. Taxes and trading costs are left out. Cash earns nothing.

"Average year" is 2016. The S&P 500 returned 12.0% that year, the calendar year closest to its average. "Long term" runs from 30 May 2007 to 11 Nov 2026, the longest stretch all nine funds cover, and is drawn week by week.

Once a month the rule looks at two things: whether the S&P 500 is below its 10-month average, and whether any of four warning signs is on. The signs come from unemployment, the yield curve, credit spreads and financial conditions.

Trend down and at least one sign on makes the rule red. After two red month-ends in a row, or sooner if the market falls fast, the rule gives a sell signal. In the tool that means the S&P 500 and Nasdaq-100 sleeves are moved to cash on the next trading day, at no cost, and bought back when the rule clears. Other sleeves are left alone.

The exact tests are not published. The results are: every state is on the record, and the tool shows the periods where the rule cost money as well as the ones where it helped.

• It does not predict anything. It shows what happened.
• It does not know your situation, your taxes or your costs.
• It does not connect to any broker or account.
• It does not recommend buying or selling anything.

Results for the crash rule before the public record began are a backtest. They use today's revised economic figures, act on every signal the next trading day and ignore the cost of hedging. They are hypothetical.

Economic data: U.S. Bureau of Labor Statistics, Board of Governors of the Federal Reserve System, Moody's and the Federal Reserve Bank of Chicago, retrieved from FRED, Federal Reserve Bank of St. Louis.

The site shows percentage changes and states only, never index levels or prices.

A do-it-yourself kit is planned: a guide and starter kit for building your own private trading workspace with AI. It gets built if enough people want it. Join the waiting list to hear when it is ready.

Questions and corrections are welcome: write to david@hindscope.com.