As a technician, you "know only what you see". That said, the "celebrated 4200 break" is not yet a done deal. Market would need to hold >4200. Until then it's a "possible false upside break/double top". And even if 4200 holds as support, there is 4325 just above... the "61% Fib retracement".... also a "logical target for a W2 bounce in a big bear market".
Unfortunately, the market can retrace all the way back to 4800-ish and still be bearish. For a new bull market, SP needs to break above and hold 4800 as support.
FWIW...