Subject: Re: Tax Loss Harvesting examined.
rayvt wrote: The idea is to occasionally sell a stock or ETF you like but which is currently sitting at a loss, to book the taxable loss. Simultaneously, use than money to buy another holding which is quite equivalent.

Beware of return reversion. Stocks with poor short-term performance tend to bounce higher. For example, starting with the S&P 500, pick the 50 stocks with the lowest return. CAGR from 1/4/2021 to 3/26/2026:

Lookback  CAGR  excess
  1008    8.0    -2.2
  504     14.5    4.3
  252     8.0    -2.2
  126     7.8    -2.4
   63     11.9    1.7
   42     17.9    7.7
   21     13.3    3.1
   10     10.8    0.6
    5     11.3    1.2
 
  RSP     10.2    0.0


P123 {S5TLH}
Universe(SP500)
FOrder("Ret%Chg(Lookback)", #Previous, #Asc) <= 50
4 week rebalance, 0% slippage