For me, it was that £1,000 I didn't invest in Amazon at the turn of the century.
For others it may be not taking a punt on Argo Blockchain only six months ago (up 5,000% since then).
But most, especially those rare active investors who know their onions, don't share the logic behind their mistakes, tending to focus on the ones that didn't get away instead.
You'll learn more about investing from reading between the lines of Monevator's Weekend Reading newsletter than I care to mention (expertly balanced by his partner in FIme The Accumulator, who lights the way for us mere mortals).
I particularly liked the insight in The Investor's "how I missed out on 4-500k of Tesla gains" post today re: how having a large mortgage weighed heavily on his investment returns between 2018 and 2019 which, if you follow his blog closely as I do, he has no-doubt more than made up for in 2020.
Anyway, I digress...but isn't that what you're here for? A bit of digression.
On that note, here's that I've been reading this past week.
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