Internet content giant Alphabet Inc. (GOOGL) was a strong momentum stock in 2017 and is set up for continued upward momentum in 2018. The company provides a suite of applications including YouTube, Maps, Ads and many others.

The stock closed 2017 at $1,053.40, up 32.9% for the year and in bull market territory at 32.2% above its 52-week low of $796.90 set on Jan. 3, 2017. The stock set its all-time intraday high of $1,086.49 on Dec. 18 and is currently trading at 3% below this level. (See also: Amazon's Digital Ad Push Threatens Facebook, Google.)

Here's how the numbers worked in 2017.

Alphabet shares closed 2016 at $792.45, and my annual risky level for 2017 was $899.21. After the close on April 27, the company reported better-then-expected earnings, and the open on April 28 was a price gap above this level, never to be tested again. At mid-year, the stock closed at $929.68, and my semiannual risky level of $1,050.84 became my upside target, which was first tested on Oct. 27. This level plus a fourth quarter pivot of $1,042.93 became magnets for the remainder of 2017.

The daily chart for Alphabet

Daily technical chart showing the performance of Alphabet Inc. (GOOGL) stockCourtesy of MetaStock Xenith

Alphabet stock has been above a "golden cross" since Aug. 18, 2016, when it closed at $802.75. A "golden cross" occurs when the 50-day simple moving average rises above the 200-day simple moving average and indicates that higher prices lie ahead. The horizontal lines show the annual pivot of $899.21 and semiannual pivot of $1,050.84.    

The weekly chart for Alphabet

Weekly technical chart showing the performance of Alphabet Inc. (GOOGL) stockCourtesy of MetaStock Xenith

The weekly chart for Alphabet is positive but overbought, with the stock above its five-week modified moving average of $1,045.40. The stock is well above its 200-week simple moving average at $728.64, which is also the "reversion to the mean," last tested during the week of Oct. 7, 2001, when the average was $249.87. The 12 x 3 x 3 weekly slow stochastic reading ended 2017 at 83.22, above the overbought threshold of 80.00.

Given these charts and analysis, investors should not add to positions at this time, but should reduce holdings on strength to my semiannual and annual risky levels at $1131.98 and $1147.06, respectively. (For additional reading, check out: Why Facebook, Netflix Are Best FAANG Stocks In January.)

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