Cramer sees Apple as an example of how important it is to stick with stocks that have proved upward momentum. Redler said Apple is due for a dip but believes those dips could be buyable. The day's drop to a 21-day moving average is a key test of support. If Apple holds on to its recent gains, Redler said, it may follow in Google's ( GOOG) footsteps. If not, Apple may move to its 50-day moving average around $644. He expects Apple to be rangebound, and trading sideways until it reports earnings Oct. 15. Redler doesn't think Apple has hit its highs for the year, Cramer said. The stock may pull back, so Cramer warned of buying on the dip. Cramer said he believes in Apple as an investor and he is not trading it. Redler said that while the stock is due for a pullback, there's still reason to believe it can rebound. So wait before you buy on the dip.