Usually the best reason to sell is you need the money or your position has gotten so large you no longer sleep well.%%
Remember the charts, on that move,[9/11] EddieMorra??
The downtrend bear market reversed,[SEPT 2011,aka 9/11] to an uptrend bull market [S&P 500/benchmark /SPY, monthly candlecharts.] Panic sellers never win ; planned sellers can win. Not a prediction.