RE: SERIOUSLY SAD2 Apr 2022 14:36
It's a cousin of the Gambler's Fallacy & Sunk Cost Bias t4g, along the lines of 'it's only a loss if I sell'. Value is eroded/amassed independently of whether you sell/buy.
In your example, your investment lost 43% (before you 'averaged down') *because* the asset came to be valued at 43% less than at some previous time. This lost value, from that point in time, is 'carried' into every future valuation, indefinitely. That your buys or sells change this *in your frame of reference* doesn't alter the underlying economics of the asset's valuation.