Ask HN: (How) do you/I apply 80/20 principle to investments of $, time etc.?

I have been listening to the Business Method podcast on 80&#x2F;20 principle [1] for a while. Maybe I have been missing something from it due to multitasking, but I am curious how to apply it to beginner level investing in stocks&#x2F;funds.<p>My (European) bank, as probably other banks also, offers some free investing services. There are some &quot;funds&quot; to invest for free, comprised from many stocks from many companies and across different sectors and managed by some human managers. There are non-free investment options with seemingly higher ROIs, but I&#x27;d like to start with the free ones. I suppose (maybe I am wrong) that these &quot;funds&quot; are mostly non-volatile and may have some stable government issued stocks etc. My bank loves green energy, so there should be lots of stocks from this sector as well.<p>How do I apply the 80&#x2F;20 principle and select the 20% of stocks&#x2F;funds producing 80% of ROIs?<p>I suppose I could collect yearly data on ROI etc, available for these stocks, feed it to some regression program. Or just visualize ROI in quartiles and select the highest. But then should I compute p values for stocks with marked increase of ROIs?<p>In the podcast Richard Koch tells that it&#x27;s easy to find high ROI companies per this principle, though may not be easy to invest in. I am a very basic level in investments with sparse knowledge.<p>How do you apply 80&#x2F;20 principle in financial&#x2F;time&#x2F;etc investments?<p>[1] https:&#x2F;&#x2F;thebusinessmethod.podbean.com&#x2F;e&#x2F;ep554-hacking-the-algorithm%c2%a0of-business-finding-billion-dollar-investments-richard-koch-author-of-the-8020-principle&#x2F;