May not have topped ...
The wave structure of Apple, which represents around 20% of NDX, suggests further upside potential under normal circumstances, although the minimum requirement for a top was met at the recent high.
Chart 1 to the right shows the larger wave structure of APPL, which has launched wave (5) of  or wave 5 of (3) of  at its August 2010 low.
As Chart 2 below shows, the count with the best look and feel is the green count, followed by the blue count. To satisfy the cardinal rule that the 3rd wave in an impulse wave cannot be the shortest, the current decline is most likely a 4th wave correction. While the wave degree of that 4th wave at the August 2010 low is ambiguous (4 of (3) or (4)?), the advance since then may not be complete. If APPL has further upside potential, so does NDX and probably the general market.
It should be noted that the minimum requirement for a top WAS met at the recent high. As far as I can see at the moment, the red count in Chart 2 offers the only way to count the recent high as the top. Chart 3 offers a squiggle count since wave [iv] of 3 of (5) under this interpretation.
However, to accept that the top is in, one needs to accept the conclusion that wave 5 of (5) was rather brief
- in its duration which is less than 2 days versus nearly a month for wave 1
- as well as in its magnitude which is 22.6 points or only 38% of wave 1.