Sorry bulls, technical analysis isn't looking so hot for U.S. equities at the moment, and Credit Suisse is piling onto your pain. 

In a new note, Ric Deverell and his team at Credit Suisse point to some technical levels worth watching, one of which could be a big signal that the top is in for the S&P 500-stock index. The index is currently trading around 1,890. 

"We have been looking for the market to retest the spike low from August at 1,867, and then medium-term support at 1,820, the October 2014 low," says the note. "With several key sectors now also falling to major support levels -- notably industrials -- and looking vulnerable,we think the risk a major top may be established has risen sharply. Below 1,867 should keep the risk lower for price and "neckline" support at 1,832/20. Below here would mark the completion of an important top, turning the core trend bearish. If achieved, we would target 1,738/30 initially -- the low for 2014 itself, and the 38.2% retracement of the 2011/2015 uptrend. Although we would expect this to hold at first, a break would be favoured in due course for 1,575/74 -- the 38.2% retracement of the entire 2009/2015 bull market."

While we've been in a sideways market for a while, a major top, according to David Sneddon on the Credit Suisse team, would mean breaking below levels such as the October 2014 low of 1,820 in the S&P.

"We've obviously already had a significant fall in the stock market, triggered by the breaking down of the lows we saw earlier this year. The big question now is whether this is just a correction in a bull market," he told us. In his mind, tumbling past 1,820 would signal that the market move could be something bigger. 

On the plus side, a move above 1,953 could help ease selling pressure, the Swiss bank said.

Credit Suisse is far from the first (or only) market participant to highlight troubling technical analysis patterns recently. A Bloomberg report earlier this month pointed to a downward sloping "head and shoulders" pattern in the Dow Jones Industrial average, suggesting further selling pressure ahead.

A "Dow Theory sell signal," one of the oldest technical indicators around, was also triggered in August when the DJIA and Dow Jones Transportation Average fell below the low of a previous selloff, set in October 2014. 

Death Crosses, Hindenburg Omens, and other imaginatively named technical indicators have also made appearances recently.