"If we do break 2,600 later this week, the next time it could ignite a move that could trigger the head-and-shoulders pattern, which then gives a measured move down to 2,300," said Scott Redler, partner with T3Live.com.
"I actually thought it would happen in 2019. I thought it would hold up a little better due to the December seasonality, and that it seemed like it might wait. But this could take any Santa Claus rally off the table," he said.
Redler said the pattern is a topping, or distribution pattern. The head represents a rounding top and the neckline serves as support. The S&P attempted to form this pattern several times in the last few years, but the support held at the neckline.
"Now that it's the ninth year of a bull run and stocks are technically breaking down, and many stocks are in a bear market pattern, maybe it ignites the move to the downside this time," said Redler.
The S&P 500 formed the so-called death cross on Friday, where its average price of the last 50 days fell below its 200-day moving average. This could signal a change in long-term trend, according to technical analysts.
WATCH: Small caps near death cross