Not a horror story, but: I had some stock options. They were in the money. I sold some and kept some. The stock went up. I sold some more, but not all of it. I was keeping an eye on my yearly income and where I shifted into the next incremental tax bracket. On December 16 (of year X), the stock price was really attractive, but I was going to pay a higher tax rate on the gains if I sold, so I decided to wait until January to sell.
On December 18, the company announced that it was buying another company. The stock market didn't like it, the price tanked, and I lost more than I would have paid in taxes.
Moral: When money is growing on trees, pick it.
But of course it's not that simple. In other circumstances, waiting could have been exactly the right move. But waiting carries risk, and I was not properly recognizing that risk.
On December 18, the company announced that it was buying another company. The stock market didn't like it, the price tanked, and I lost more than I would have paid in taxes.
Moral: When money is growing on trees, pick it.
But of course it's not that simple. In other circumstances, waiting could have been exactly the right move. But waiting carries risk, and I was not properly recognizing that risk.