The Nasdaq Composite has produced a “death cross” chart pattern on Monday, joining the other three major market indexes, which have produced similar bearish chart patterns over the past couple months.

History suggests this occurrence could weigh on the broader stock market over the shorter term, but it’s not quite the death knell for the market over the longer term that the pattern’s name might suggest, according to data provided by Sundial Capital.

A death cross appears when the 50-day moving average crosses below the 200-day moving average, an event that many chart watchers view as marking the spot a shorter-term correction morphs into a longer-term downtrend.

“If we’re operating under the theory that this is a sell signal for stocks, then [historical data] don’t support the assumption,” said Jason Goepfert, president of Sundial, in a note to clients.

The Nasdaq’s COMP, +1.71% 50-day moving average fell to 4,913.44 in morning trade from 4,923.91 on Friday, according to FactSet, while the 200-day moving average inched up to 4,917.62 from 4,917.61. That’s the first death cross for the index since Dec. 19, 2012.

The Nasdaq fell 2% in midday trade, and has dropped 12% since its July 20 record close of 5,218.86.

The Nasdaq’s death cross completes the cycle, as the pattern has appeared in the charts of the Dow Jones Industrial Average DJIA, +0.51% on Aug. 11, for the S&P 500 index SPX, +1.05% on Aug. 28 and for the Russell 2000 Index RUT, +0.78% on Sept. 2. Read more about the spread of the death cross.

Since their death crosses appeared, the Dow has slumped 7.5%, the S&P 500 has shed 4.6% and the Russell 2000 has lost 3.8%.

Monday marks the first time since Aug. 24, 2011, that all four indexes fell under the death cross spell at the same time, and just the 13th time since 1979, according to Sundial.

“Returns in the S&P [500] were weak in shorter-term of less than one month, though they did not meet the test for significance,” Goepfert said. “After a month, returns improved significantly. Three months later, the S&P [500] was higher 9 out of 12, and only one of those losses was meaningful.”

S&P 500 performance after S&P 500, Dow industrials, Russell 2000 and Nasdaq Comp all produce death crosses (DC) since 1979 Signal Last index to produce DC S&P 500 % gain/(loss) 1 week later S&P 500 % gain/(loss) 1 month later S&P 500 % gain/(loss) 3 months later S&P 500 % gain/(loss) 6 months later S&P 500 % gain/(loss) 1 year later 4/23/1980 Russell 2000 2.5 5.1 17.5 27.1 29.1 9/11/1981 Russell 2000 (4.4) (0.3) 3.4 (10.7) (0.5) 2/23/1984 Dow 2.5 1.7 (0.7) 8.3 16.8 11/06/1987 Dow (1.9) (6.2) (0.5) 2.4 10.3 3/19/1990 Dow (1.7) (0.8) 3.9 (7.5) 8.3 5/23/1994 Russell 2000 0.7 (0.0) 2.0 1.8 15.5 9/30/1998 Nasdaq Comp (4.6) 6.8 21.1 27.2 26.1 11/15/2000 Dow (4.9) (5.6) (6.4) (7.0) (18.2) 8/18/2004 S&P 500 0.9 3.0 7.3 10.5 11.4 1/17/2008 Nasdaq Comp (0.2) 1.2 4.3 (5.4) (36.2) 7/28/2010 Russell 2000 1.9 (5.3) 7.2 17.2 18.0 8/24/2011 Dow 3.5 (4.1) 1.3 15.8 20.0 Average S&P 500 % gain/(loss) (0.5) (0.4) 5.0 6.6 8.4 Statistical relevance (%)--above 95% suggests significance 4 73 25 6 28 Source: Sundial Capital Research, SentimenTrader.com

Goepfert says the fact that the data show little statistical significance, between a death cross grand slam and the performance of the broader stock market, doesn’t mean it can’t still be useful to investors.

“It’s as useful to know what to ignore as what not to, and this is one to ignore,” Goepfert said.

Among other broader-market indexes, death crosses appeared for the NYSE Composite Index NYA, +0.32% on Aug. 11, the Dow Jones Transportation Average DJT, +0.76% on May 26, the S&P Mid Cap 400 MID, +1.01% on Aug. 31 and the Wilshire 5000 Total Market Index W5000FLT, +0.99% on Aug. 28.