As others have said, averages aren't useful unless the behavior matches the average.

If those 147 4% drops actually happened every 100 days or so then it's not newsworthy or interesting, just an occasional correction.

If those 147 days happened all in a row that would mean the nasdaq dropped to 0.25% of its original value in about 4 months, which would be catastrophic.

The real answer is presumably somewhere in the middle, but the specifics are what determines if it's worth noting or not.