[[Start here]] → [[maintain your discipline|discipline]] → [[when to sell]] → the 90/70 rule --- The biggest hazard in investing is falling in love with your stocks. We get to know a company, we trust the management, we want to see a hollywood ending. As a result, our sell discipline gets thrown out of the window. No matter what the fundamentals say, we tend to keep holding. The power of [[simple rules beat human judgement|simple rules]] is well understood. Simple rules beat human judgement. One of my favourite rules for selling is based upon a paper by Christoph Reschenhofer called [[Reschenhofer - Combining Factors|Combining Factors]]. It’s so simple it’s daft. Every time I break it, I regret it. His approach was to rank stocks between 0 and 100 (yes, very similar to the StockRanks at Stockopedia). He found that the optimal buy/sell point for large high-ranked QVM stocks was around 90 (for the buy) and 70 for the sell. Or more accurately: - **For smaller cap shares:** Buy at a rank of **92**, Sell at a rank of **72**. - **For larger cap shares:** Buy at a rank of **94**, Sell at a rank of **74**. His "rules" were optimal points among a wide range of good choices, as shown in the graphic below. Purchasing above ~90 and selling at any cut-off down to ~50 (the green squares) does work fine… but returns are optimised at sell ranks above 70. ![[the-90-70-rule.png]] We know that high ranked stocks (90+) tend to significantly beat the averages. We know that average returns accrue to stocks below a rank of 70. So why over-complicate it? Keep life simple. Buy above 90, sell below 70. The 90/70 rule. * See [[Reschenhofer - Combining Factors]]