DD Support Board and Research Team

[bar1080]

Ah Davidsson, you read that Mathinvestor.org. When I became interested in stocks as a kid, an uncle exposed me to "backtesting overfitting" using an example similar to DH Bailey's in that pdf, of a fraudster who sends out diminishing numbers of stock tip letters to prospective clients. Uncle, didn't use highfalutin' math and the modern terminology, "backtest overfitting," appears to be of very recent origin. Google finds that term exists exclusively within the past ten years. However its main idea is ancient.

If you enjoy that sort of thing, you'll value the investment-related papers of Professor Terrance Odean of Berkeley. By all means, read his often-cited "The Common Stock Investment Performance of Individual Investors."
https://www.bogleheads.org/wiki/Terrance_Odean

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=94140

It's vital that investors understand why almost all stock investors, including professionals, lag the major indexes. Odean's key takeaway is, "The More You Trade, The More You Lose."