Today I sold most of my Apple shares at $172.55 per share. My thinking was that I should capture most of my profit now to be safe, but leave room for me to sell some of my shares at a higher price if Apple happens to go higher. (Though, knowing what I know now, I don't know that the stock is going to be much higher than this anytime in the near future.)
I almost sold all of my Google stock this morning, but decided not to sell any of it when I found out that they had just released their own
web browser. My thinking was that the stock would go up at least $10 per share, but I figured it could go up a lot more than that, so if I sold it after it when up $10, I could be missing out. I figured it would be safe to wait a day, then sell after that. I think I might have been wrong:

Had I entered my order as I originally planned to, I may have been able to sell Google as high as $480 per share, which is $14.75 more per share than it is now.
I tried to find a reason for why the stock began to take a dive around 1:30 PM, and according to
this article the reason seemed to be because the Federal Reserve released the minutes to the meeting held on August 5th. In these minutes, it indicated that three of the Fed districts had a desire to increase interest rates. When people who control loads of money in the stock market found this out, they pulled a lot of money out of the stock market because it makes less sense to have money in the stock market when interest rates are higher, so this caused various stocks, like Google and Apple, to decline in value through no fault of those companies.