1 Across the board
2 Short squeeze
3 FAANG market cap driven
#1 is real
#2, #3 can only be detected by breadth indicators's divergence:
a. most shorted stocks rally
b Equal-Weigh vs Market cap
c Tons of breadth indicators
See Below
1/7
2/7
Great read:
The Complete Guide to Market Breadth Indicators: How to Analyze and Evaluate Market Direction and Strength
by Gregory Morris (Author), Tom McClellan (Foreword)
Others I have to implement myself.
The goal is to estimate and predict the breadth of all major Indexes and Sectors using all these indicators for market strength and weakness measurement; hence the divergence and convergence, etc
All these breadth indicators can be implemented in such a way that it can be applied to a group of stocks (like SPY, RUT, NDX, MID, XLK, XLY, XLP components stocks), so as to measure the breadth strength & weakness from different perspective for major indexes and sectors.
Greg Morris implemented hundreds of his breadth indicators described in his book with MetaStock charting and testing software.
Quite a collection of breadth indicators. You can see from my list
He is also the author of some popular "Candlesticks" chart patterns books.