The Affordable Care Act, aka Obamacare, became the law of the land on March 23, 2010, and many of the major providers of health insurance options on the HealthCare.gov exchanges have left or are threatening to leave if their annoucned mergers are blocked.

Aetna (AET) wants to buy Humana (HUM) - Get Report  while Anthem (ANTM) - Get Report wants to buy Cigna (CI) - Get Report . For these health insurance providers, the mergers are designed to reduce costs. However, U.S. regulators are balking on fears of reduced competition. That's prompting some providers to leave Obamacare in states where they can't make a profit.

The anticipation of mergers and the future of Obamacare have caused volatility among the four stocks below. The weekly charts are similar as three of four have negative weekly charts, while Humana's weekly chart is positive.

Daily charts will show the Fibonacci retracement levels of the huge rallies from lows set on Oct. 15, 2014, to the highs set between May 29, 2015, and June 26, 2015. All four are trading between key retracement levels as the hype of Obamacare began to fade a little more than a year ago.

Here's a scorecard for the four health insurance stocks.

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Here's the daily chart for Aetna.

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Courtesy of MetaStock Xenith

Aetna closed Tuesday at $116.87, up 8.1% year to date and in correction territory 13% below its all-time intraday high of $134.40 set on June 26, 2015. Despite this decline the stock is 62.7% above its Oct. 15, 2014 low of $71.81.

The horizontal lines are the Fibonacci retracement levels of the rise from the 2014 low to the 2015 high. The 2016 low of $92.42 set on Feb. 9 was just below the 61.8% retracement of $95.71. Strength since this low has the stock trading around its 23.6% retracement of $119.64 since June 2.

A negative weekly chart for Aetna is an investor warning. Investors looking to buy Aetna should consider doing so weakness to $68.48 and $65.13, which are key levels on technical charts until the end of 2016.

Investors looking the reduce holdings should consider doing so on strength to $121.47, which is a key level on technical charts until the end of this week.

Here's the daily chart for Humana.

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Courtesy of MetaStock Xenith

Humana closed Tuesday at $178.47, flat for the year to date and in correction territory 18.8% below its all-time intraday high of $219.79 set on May 29, 2015. Despite this decline the stock is 47.4% above its Oct. 15, 2014, low of $121.04.

The horizontal lines are the Fibonacci retracement levels of the rise from the 2014 low to the 2015 high. Note that the sideways to down retracement has not been able to sustain strength above its 38.2% retracement of $182.07. The 2016 low of $150 set on July 19 was well below the 61.8% retracement of $158.74. Recent strength had the stock testing the 38.2% retracement again at $182.07 on Aug. 12.

A positive weekly chart will end given a close this week below its key weekly moving average of $176.57.

Investors looking to buy Humana should consider doing so weakness to $172.27, which is key level on technical charts until the end of this week.

Investors looking the reduce holdings should consider doing so on strength to $181.51, which is a key level on technical charts until the end of this week. A higher sell level is $201.92 in play until the end of 2016.

Here's the daily chart for Anthem.

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Courtesy of MetaStock Xenith

Anthem closed Tuesday at $125.42, down 10.1% year to date and in bear market territory 27.7% below its all-time intraday high of $173.59 set on June 22, 2015. Despite this decline the stock is 15.1% above its Oct. 15, 2014, low of $108.92.

The horizontal lines are the Fibonacci retracement levels of the rise from the 2014 low to the 2015 high. Note that the sideways to down retracement was to a 2016 low of $115.63 set on Feb. 8, well below the 61.8% retracement of $113.66. A subsequent rebound to $147.99 on April 22 was below the 38.2% retracement of $148.92. The stock is currently well below its 61.8% retracement of $133.66.

A weekly chart is negative with the stock well below its key weekly moving average of $129.43.

Investors looking to buy Anthem should consider doing so weakness to $85.91, which is key level on technical charts until the end of 2016.

Investors looking the reduce holdings should consider doing so on strength to $130.15, which is a key level on technical charts until the end of this week.

Here's the daily chart for Cigna.

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Courtesy of MetaStock Xenith

Cigna closed Tuesday at $128.22, down 12.4% year to date and in bear market territory 24.9% below its all-time intraday high of $170.68 set on June 26, 2015. Despite this decline the stock is 49.5% above its Oct. 15, 2014, low of $85.75.

The horizontal lines are the Fibonacci retracement levels of the rise from the 2014 low to the 2015 high. Note that the sideways pattern has been centered of the 38.2% retracement of $138.24 between Aug. 24, 2015 and July 28, 2016. Strength in between has been below the 23.6% retracement of $150.65. The 2016 low of $121.87 was set on June 27 and Tuesday's close of $128.22 was right on the 50% retracement of $128.22.

The weekly chart is negative with the stock well below its key weekly moving average of $130.70.

Investors looking to buy Cigna should consider doing so on weakness to $94.56, which is a key level on technical charts until the end of 2016.

Investors looking to reduce holdings should consider doing so on strength to $135.36, which is a key level on technical charts until the end of this week.

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