After the ubiquitous ramp into the US cash market open, things have gone a little pear-shaped, with stocks tumbling back below last week's lows and pushing critical 2018 support levels.

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As BMO's Russ Visch writes,

It’s a “make or break” day for the S&P 500, which closed right at key support at its October/November lows (2630) on Friday. If support holds here over the next few days it would build the case that a bottom is beginning to form here. Alternatively, a close below that level would signal a resumption of the long-term downtrend with a measurable downside swing target of 2445.There is support at the early 2018 lows in the 2530-2560 zone but in our opinion it will take a close below that level to cause the volatility/capitulation spike that’s been missing so far.

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In our opinion, a breakdown appears to be the most likely outcome given that other, broader measures of equity participation such as the Russell 2000 and Value Line Composite indexes have already broken down.

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At the same time NYSE breadth data is getting worse, not better. Late last week the number of stocks making 52-week new lows on the NYSE jumped to its highest reading in nearly three years.

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The deterioration “underneath the surface” which these indicators reflect typically only accompany continuation patterns (pauses within downtrends) not bottoming processes.  

And that's what just happened...

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Breaking below the Oct lows...

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