SledgeKey Backtests
Classic strategies, tested two ways
Every strategy here is backtested twice over the same window: once on a survivor-only universe, the way most free tools quietly do it, and once with the companies that went bankrupt, were seized, or left the exchange kept in. The gap between the two results puts a number on survivorship bias. Each page discloses its full methodology, and reading any of it requires no account.
Midcap Value
P/E under 15 and a $2B–$20B market cap band, held from 2017 through 2026. The survivor-only run kept pace with SPY, while the honest run, which had to carry Silicon Valley Bank into its collapse, trailed the index by 1.4 points a year.
Live
The Magic Formula
Joel Greenblatt's earnings-yield-plus-return-on-capital screen from The Little Book That Beats the Market, run both ways on point-in-time data.
Coming Soon
Piotroski F-Score
The nine-point fundamental checklist from Joseph Piotroski's 2000 paper, tested for whether high-F-score value stocks still hold up when the casualties stay in.
Coming Soon
How these backtests are run
Every page discloses its complete configuration: every filter, threshold, weighting rule, rebalance schedule, and cost assumption. The universe is NYSE and NASDAQ operating companies (no SPACs, REITs, ETFs, or funds) built point-in-time, so eligibility at each rebalance reflects the companies actually listed on that date. In the honest runs, holdings that delist are booked out at their frozen last traded price. In the survivor-only runs, later-delisted companies are excluded from the universe entirely, which is what most free backtesting tools silently do.
When a strategy loses to the index, the page says so, and every analysis carries a caveats section listing what the result fails to establish.