The most difficult thing in the world is to trade during market booms - yes you can day trade and be successful as long as you stay within the constraints of a few hours. But the trading community is so skitterish during market run-ups that they are ready to sell and buy (in that order) anything on just about any news.
I wrote this on stockbee awhile back (I still like that guy) and it was so simple and profound I thought I'd open the BLog and repost it here: Buying all time highs or other high mark is a sucker's play - yes every once in awhile you will make some coin (witness GOOG which traded at all time highs for several months and then, suddenly, stopped and is now just so much dead money).
But many times you will be the bag holder in a very bad trade (PNTR comes to mind immediately - put up a 1 year chart of PNTR and imagine the guy who bought at 24).
Never buy a stock unless you have two numbers in mind - both exits - one above the price you paid and one below. If you hold above the upper number be ready to dump if it retraces to your target and never hold below your lower number.
If you follow that simple approach you can buy any stock at any price at any time. Remember learning how to trade is learning how to lose - anybody can learn how to win - it's the losing that is troublesome.
If you adhere to that last paragraph and just apply some selection discipline you can make money in any kind of market - up or down.
Stockbee has a number of methods that he uses to buy stocks that have retraced some from their all time highs. This is known as buying stocks in the Trader's Action Zone (TAZ) which is highlighted on Taz Trader's site where you can also pick up some great tips for trading. Both of these sites are on my link list.
Come back about once a week because I'm working on a method whereby wage slaves such as myself can still short-term trade with only one or two visits to the market every day. Eventually I'll get it and I will publish it here.