NDX:watch the 2268.30 level
Initial confirmation of a meaningful top in NDX (either minor wave 3 (more likley) or minor wave 5) is likely at the BOY high of 2268.30 as indicated in Chart 1. Note that 2268.30 is 2.72% below the recent high and 1.52% below today's close.
Today's better-than-1% decline leaves us with two competing tracking counts.
The red count calls for a top being in place. If so, other indexes probably have topped as well - either as the top or a meaningful interim top. See Hope Rally Ends Here (Jan 2011 attempt) (1/14/11) for additional discussions.
The green count sees an expanded flat for  of iii and thus sees today's decline as wave iv of (v) of [v]. There are a number of things going for this count.
a- Wave  of iii alternates with wave  of iii.
b- Wave iii channels well as indicated by the green channel lines.
c- The decline from the recent high counts as a (potentially incomplete) zigzag so far (Chart 2), possibly wave [A] of a triangle iv or the entire wave iv.
d- Today's low came at the lower boundary of the wave (v) trend channel as indicated by the blue trend line.
A decline below 2268.30, the top of wave i of (v), will reject the green count and confirm a meaningful top. The same can be said about COMPQ.
Chart 3 presents the two tracking counts on SPX.
The blue count sees a top. Or is wave [v] extending based on the gray count? Breaching the BOY high as well as the blue [iv] low is important to eliminating this bullish potential.
The green count sees today's decline as wave [iv] of 5. Note that today's low also rests on the lower boundary of the trend channel for minor wave 5 if the green count is playing out.
Here's an update on the wave structure of INDU with three tracking counts discussed in recent days.
The blue and red counts see the top being in place. The green count warns of an incomplete ED in the Dow (Chart 4 and Chart 5). If the incomplete ED played out, it would meaningfully tilt the odds towards the bullish counts discussed above.
Moreover, the squiggle count (right Chart 6) shows a distinctively corrective decline (so far) in the Dow.
These counts (Chart 7) on the RUT are inspired by Matt's comment in the comment section. The red count sees a top in place. The green count has wave (iv) being an expanded flat (or a triangle?), which would alternate with the zigzag wave (ii). Today's low comes close to the mid-channel line based on the green count.
Squiggle counts discussed yesterday are still tracking, with an ED possible on senior indexes.