I am long for the long haul now to SPX's target.
Long QQQ and SPY.
IMO we have bottomed, we didn't retest the 99 target at 537 and support is holding.
On the off chance we break below the 537, then yeah, we would look for the cubic mean in the 520s (current 528), but I just see it as being unlikely.
I won't update on SPY anymore because there is nothing more to say until we hit the target.
Good luck!