General Dynamics (GD) - Get Report , Lockheed Martin (LMT) - Get Report and Northrop Grumman (NOC) - Get Report gapped higher in tandem on Nov. 9 following the election victory by Donald J. Trump. These stocks peaked between Nov. 29 and Dec. 5, and were hit by a Trump tweet on Dec. 12, in which the president-elect lambasted the "out-of-control" cost of the F-35 joint Strike Fighter jet being built by Lockheed Martin. Weakness to the Dec. 12 lows provided buying opportunities for the three stocks.

Each defense stock is above a "golden cross" on the daily charts. A "golden cross" occurs when the 50-day simple moving average rises above the 200-day simple moving average and signals that higher prices lie ahead. These bullish formations remain in play today.

General Dynamics has been above a "golden cross" since June 6, when the stock closed at $140.04. Lockheed has been above a "golden cross" since July 29, 2015, when the stock closed at $208.15. Northrop Grumman has been above a "golden cross" since April 16, 2015, when the stock closed at $71.29.

The weekly charts show a red line through the price bars, marking the key weekly moving average (a five-week modified moving average). The green line is the 200-week simple moving average, the "reversion to the mean."

The study in red along the bottom of the chart is weekly momentum (a 12x3x3 weekly slow stochastic), which scales between 00.00 and 100.00, where readings above 80.00 indicate overbought and readings below 20.00 indicate oversold.

A negative weekly chart shows the stock below its key weekly moving average, with weekly momentum declining below 80.00 in a trend toward 20.00. A positive weekly chart shows the stock above its key weekly moving average, with weekly momentum rising above 20.00 in a trend toward 80.00.

Here's the weekly chart for General Dynamics.

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Courtesy of MetaStock Xenith

General Dynamics closed Wednesday at $174,10, up 26.5% year to date. It is in bull market territory, 43.2% above its Jan. 20 low of $121.61. The all-time intraday high of $180.09 was set on Dec. 5 and the stock is 3.3% below this high.

The weekly chart for General Dynamics is positive but overbought, with the stock above its key weekly moving average of $168.99. The stock is well above its 200-week simple moving average of $123.47, last tested as the "reversion to the mean" during the week of April 26, 2013, when the average was $67.27. The weekly momentum reading is projected to slip to 83.98 this week, down from 84.68 on Dec. 16, with both readings above the overbought threshold of 80.00.

Investors looking to buy General Dynamics should do so on weakness to $155.42, which is a key level on technical charts until the end of 2016. Investors looking to reduce holdings should consider selling strength to $180.42, which is a key level on technical charts until the end of 2016.

Here's the weekly chart for Lockheed Martin.

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Courtesy of MetaStock Xenith

Lockheed Martin closed Wednesday at $252.52, up 16.3% year to date. It is 6.4% below its all-time intraday high of $269.90, set on Dec. 5. The stock is in bull market territory, 26% above its 2016 low of $200.47, set on Jan. 26.

The weekly chart for Lockheed Martin is negative, with the stock below its key weekly moving average of $253.98, and still well above the 200-week simple moving average of $184.02. The stock has been above its 200-week SMA since the week of Jan. 20, 2012, when the "reversion to the mean" was $81.10. The weekly momentum reading is projected to decline to 70.46 this week, down from 74.84 on Dec. 16, as the stock continues to suffer from F-35 fallout.

Investors looking to buy Lockheed Martin should consider doing so on weakness to $251.66, which is a key level on technical charts until the end of 2016. Investors looking to reduce holdings should consider selling strength to $273.85, which is a key level on technical charts until the end of 2016.

Here's the weekly chart for Northrop Grumman.

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Courtesy of MetaStock Xenith

Northrop Grumman closed Wednesday at $233.15, up 23.5% year to date. It is in bull market territory, 33.2% above its Jan. 28 low of $175.00. The stock set its all-time high of $253.80 on Nov. 29, and is 8.1% below this level.

The weekly chart for Northrop Grumman is negative, with the stock below its key weekly moving average of $235.37, and still well above the 200-week simple moving average of $151.11. The last test of this "reversion to the mean" occurred during the week of Nov. 25, 2011, when the average was $54.18. The weekly momentum reading is projected to decline to 70.75 this week, down from 78.83 on Dec. 16.

Investors looking to buy Northrop Grumman should consider doing so on weakness to $220.72, which is the Dec. 12 low. Investors looking to reduce holdings should consider selling strength to $238.74, which is a key level on technical charts until the end of 2016.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.