In practice, to which extent do you quantify the effect of commissions+slippage on your actions ? Supposidly, we’ll almost always enter/exit outside of the precise time of the buy/sell of the mass followers leading to divergence. Nonetheless, it represents locked losses more than buy&hold forever. I fear that, for myself, intervening too often, might have a counter-productive effect. I am debating over once a month drastic arbitrage (instead of quantity touch-up) being too much.