By Daniel Kline Selling all your stocks to buy them back at lower prices is a terrible idea. When the stock market crashes it impacts people in different ways. Nobody likes seeing their net worth drop — even if it’s just on paper — and it’s very tempting to want to stop the bleeding and sell your holdings. That’s an understandable impulse. When you see your stocks lose value, it’s easy to think about selling them simply to stop the bleeding. You can’t lose any more money if you sell, but that’s a very risky attitude. Nobody knows when the market will reach bottom and the bottom may not happe…