There is a concept in the stock valuation biz called "perfect pricing". To some of us, that's a black flag; the race is over. To others, however, it merely means that conventional investment analysis based on Graham and Dodd can be dismissed on account of overriding Quality considerations.

I think we can agree that (at $116.28) EBAY is perfectly priced; however, if you are seeking Growth At a Reasonable Price (GARP) or good Value, then you are likely not interested in EBAY (the stock). Perfect pricing suggests that in order to stay invested the investor is willing to take all the risk. For buy-and-hold investors, that's probably not a good idea.

Now you do know that risk can be an open-ended subject. There are risks related to the stock market prices, credit/solvency, independent business valuation, and management performance, among others. In fact, if you are a classic worrier, the list of risks becomes endless.

But the skinny on risk is that the more of it, the shorter ought to be your hold period.

Since I like EBAY's biz model, and I know EBAY has millions of happy customers, I am prepared to trade the stock. However, in my book I cannot find it in me to more than day trade a stock that has a price-to-earnings multiple north of say four times the S&P multiple.
Since EBAY trades at something like a 111 PE, my time horizon for long trades is measured in minutes, possibly hours. Even with short trades, my window would be hours to days, but never weeks.

Simply put, the risk of "news" is too great for me to accept. A lot of market news, you know (or ought to in case you don't), is fabricated in order to cause you to buy or sell stocks.
Since I'm not in the room (with these "news" creators), I'm out of the deal. In that regard, I'm just like you; when the spin begins, you and I are not privileged to know which way the stock is headed.

EBAY is a super company but, at any point in time (usually to start a day, right after the close the night before when this group has taken protective put/call option positions), investors could get hammered by a change in tactics by a large Wall Street or foreign capital trading pool (say five or ten houses working together).

Of course these "raids" are not supposed to happen in "free" markets, but they do!

What I might do, if I were long the stock is to write short-term (3 to 4-month) calls whenever I thought the stock was technically over-bought, and to write short-term puts (prepared to buy the stock at much lower prices if the stock was put to me) whenever I thought the stock was technically over-sold.