Method

Data

Daily prices and financial statements for Tokyo Stock Exchange stocks from JPX's J-Quants API, including delisted companies (testing only survivors flatters results). No raw prices or individual stock names are published on this site.

TOPIX is proxied by the 1306 ETF with distributions; the all-world index by the ACWI ETF converted to yen. Like an accumulating fund, the all-world index is taxed only when sold at the end.

Period

2017-07-03 to 2026-09-30, about 9.2 years. Strategies that use 12-month returns need a one-year warm-up, so the test falls a little short of ten years.

Verdicts

• Won: higher after-tax annual return over the whole period, and beat the benchmark in at least 60% of 75 three-year runs starting at the beginning of each month
• Mixed: only the annual return was higher, or it was lower but at least 40% of runs won
• Lost: everything else

Strategy choice, exit rules and verdict rules were fixed before tallying. Choosing the best combination afterwards would pick up luck.