Research

Read the English studies, including how each test was run, what it found, and what remains uncertain.

Read every study without an account. Each date is labeled as the original Japanese publication or the English publication.

Open access Published in English 2026-11-10 What did your account earn? A guide to time-weighted return Deposits can lift a brokerage balance without producing investment gains. Learn how time-weighted return separates the two, and why the benchmark, dates and drawdowns still matter.
Open access Published in English 2026-11-08 Does Letting AI Think More Improve How It Picks Stocks? We gave the same AI model a larger reasoning budget on 100 earnings reports. The simulated account met its preset target, but the 17 changed decisions and a comparison with equal numbers of picks did not show better stock selection.
Open access Published in English 2026-11-08 Did Financially Strong Stocks Beat an S&P 500 ETF? Financial quality helped rank stocks in historical tests. After costs, corrected portfolio estimates were positive versus an S&P 500 ETF, but both uncertainty intervals included zero.
Open access Published in English 2026-11-08 Can a Whole-Share Basket Replicate a Momentum ETF? A 100-stock replica tracked SPMO closely. A simulated account targeting its top 20 stocks in whole shares trailed an S&P 500 ETF-based comparison.
Open access Published in English 2026-11-08 Does Limiting Investment in Stocks That Move Alike Improve Results? If investment is kept from concentrating in stocks that move alike, by limiting the total held in each group at the time of purchase, how do results change? In simulations of 25% and 30% caps, we did not find a consistent improvement over having no cap.
Open access Japanese original published 2026-10-26 Do Stock-Price Regularities Still Pay After Trading Costs? We tested four stock-price regularities reported in academic papers, including trading costs and splitting the data into separate periods. None met the pass criteria set in advance, and the four fell short for different reasons.
Open access Japanese original published 2026-10-07 Testing Minervini's Trading Method: A 16-Year Backtest We turned US trader Mark Minervini's method into fixed trading rules and tested them on 16 years of historical data. Both methods we could compare trailed the S&P 500-tracking ETF.
Open access Japanese original published 2026-09-29 Does Raising Cash Using the 200-Day Moving Average Reduce Losses? We tested a rule that raises cash to at least 60% when both the S&P 500 and Nasdaq-100 fall below their 200-day moving averages. It added little because the existing rules already held substantial cash. This simplified test has limits.