Tests can now go back up to 20 years

Until 8 October the Strategy Agent tested a rule over 10 years at most. The limit is now 20 years.

How to ask. Say the period in your own words: "over the last 20 years", "the last 15 years". If you ask for more than 20, nothing runs. The agent says what the limit is and offers the 20-year version in one step.

When a share is younger than the period. A test starts on the first day every share in it has a price. Ask for 20 years on a share that was listed 8 years ago and the test covers those 8 years. The agent says so before it runs, and names the share that shortened it. The same holds for the fund a result is compared with: a test never runs on dates that fund does not cover.

What a longer test does not tell you. More years means more kinds of market in the test. It is still a test of the past. It is not a forecast and it is not advice.