I have and don't agree with them. I'm more in the camp of O'Niel, Darvas and Minervini. I out perform BRK.
He may not have sold at a loss, but he is sitting on a loss at this moment in time. How else would you describe a decline in the value of holdings, irrespective of what the intention may be?
A trade or investment. No profit or loss till trade is closed. Same when in a paper profit. Don't count your chickens till they hatch. Why is the concept hard to understand?
So then you would regard an investment that went down 90% in value as roughly the same as one that went up 10-fold simply because neither one was closed out?
It is hard to understand when you step from the individual trade. Your brokerage sends you a statement at the end of each month. The value of your investments change. Your liquid networth is calculated based on the current price of your assets. It would be hard to put up a security as collateral for a loan based on the price you paid for it,especially if the value has dropped. The only ones who care what you paid for an asset is you and the taxman. If your liquid net worth is dropping each month then you are losing money. Trying to convince yourself otherwise is only fooling youself. Nobody lies to themselves worse than a trader who is underwater.
Hope you wrote that tongue-in-cheek because that line of thinking is only used by losers and scammers. If you have an asset that is 90% down, try to go to a bank and use it as a collateral valued at the purchase price, tell me if they smirk, laugh or ridicule you. Everything is mark-to-market.