Ann: Ceasing to be a substantial holder, page-125

Normally I don't like to set stop losses on such fundamental investments. You need to comfortable with a 50% paper loss if you want to be an investor, as Buffet says. But very hard to predict that kind of price action today.

I've been a few companies where a big holder has decided to liquidate after 80%+ losses and I learnt that no price is too low when they choose to liquidate! Only convicted buyers (hopefully funds) will step in, but as you can see today they waited until a 'safer' technical support level (double bottom) before they buy big.