Twitter hit the ground again as solar stocks took to the skies. Solar stocks were able to soak-up some extra sunlight with one less obstruction in the sky on Monday.  After falling 13.04 percent on Friday, Twitter (NYSEARCA:TWTR) fell another 5.08 percent on Monday to close at the overpriced level of $60.51 per share.  The result brought Twitter’s relative strength index down from 66.07 to 61.07.  Most investors consider an RSI above 70 as an “overbought” signal.

Without that little bird blocking the sun, solar stocks went on a tear during Monday’s session.  The Guggenheim Solar ETF (NYSEARCA:TAN) climbed 2.73 percent to $35.78.  Real Goods Solar (NASDAQ:RSOL) jumped 8.90 percent to $3.06, getting back above its 50-day moving average for the first time since November 18.  SunPower (NASDAQ:SPWR) vaulted 4.53 percent to $30.22.  Canadian Solar (NASDAQ:CSIQ) soared 3.87 percent to $30.32.  With a 0.74 percent surge to $57.35, SolarCity (NASDAQ:SCTY) is forming another flag on its chart after completing a bullish, inverse head-and-shoulders pattern.  This stock has been alternating its up and down days.  As a result, we might see this stock make a nice move on Thursday  … or Friday …  First Solar (NASDAQ:FSLR) advanced 0.62 percent to $55.60.

The chart below depicts the performance of the Guggenheim Solar ETF during the past six months.  (Chart courtesy of Stockcharts.com).

As the chart indicates, after finishing Monday’s trading session with a 2.73 percent jump to $35.78 per share, TAN climbed to a point which was 3.94 percent below its 50-day moving average of $37.25.  The Relative Strength Index for TAN is 51.35.  The MACD is climbing above the signal line, suggesting the likelihood of a continued advance.

The 3D printing sector had a generally good day on Monday, although Friday’s big gainer, ExOne (NASDAQ:XONE) was almost back to where it was on Thursday night, after finishing Monday’s session with a 3.94 percent drop to $63.64.  3D Systems (NYSEARCA:DDD) climbed 1.28 percent to $91.95.  Stratasys (NASDAQ:SSYS) soared 1.19 percent to $130.53.  3D bioprinting company, Organovo Holdings (NYSE MKT:ONVO) jumped 5.71 percent to $9.81.

The biotech sector had a decent session on Monday, with three of the four major biotech ETFs finishing in positive territory.  One of Monday’s standout biotech stocks was Galena Biopharma (NASDAQ:GALE).  After jumping 5.40 percent on Friday, Galena followed through by skyrocketing 12.35 percent on Monday, to close at $4.82.  The SPDR S&P Biotech Index ETF (NYSEARCA:XBI) advanced 0.30 percent to $130.23.  The Market Vectors Biotech ETF (NYSEARCA:BBH) rose 0.29 percent to $88.51.  The iShares Nasdaq Biotechnology Index ETF (NYSEARCA:IBB) climbed 0.41 percent to $226.84.  The First Trust NYSEARCA Biotechnology Index ETF (NYSEARCA:FBT) was the only member of the group to finish in the red.  FBT declined 0.16 percent to end the day at $69.36.

The major ETFs expected to respond to developments in the technology sector are:

Technology Select Sector SPDR ETF (NYSEARCA:XLK):  -0.20%

Vanguard Information Technology Index ETF (NYSEARCA:VGT):  -0.10%

iShares Dow Jones U.S. Technology Sector Index ETF (NYSEARCA:IYW):  -0.13%

Market Vectors Semiconductor ETF (NYSEARCA:SMH):  +0.50%

iShares PHLX SOXX Semiconductor Sector ETF (NASDAQ:SOXX):  +0.17%   Learn More About iShares ETFs

Bottom line:  Twitter (NYSEARCA:TWTR) was grounded on Monday, after falling a total of 19.02 percent over a two-day period.  Meanwhile, the solar sector continued to recover from its early-December slump.