The S&P 500 Index is likely going to extend its two-week decline to hit its 200-day moving average at 2,356 points, BMO technical analyst Russ Visch said in a Monday note.

Indicators are "universally negative" in the medium-term, Visch wrote. BMO sees daily breadth and momentum indicators remaining negative and not yet oversold, signaling short-term trends are set to stay negative, as well.

The predicted decline to the index's 200-day moving average would represent a 5% drop from the S&P's all-time closing high of 2,480.91 reached on August 7. A fall that dramatic hasn't happened since June of last year.

The S&P 500 trended barely up 0.03% to 2,426.20 at midday Monday.

More of What's Trending on TheStreet: