In trading on Friday, shares of Transportadora de Gas del Sur S.A. (TGS) entered into oversold territory, changing hands as low as $19.45 per share. We define oversold territory using the Relative Strength Index, or RSI, which is a technical analysis indicator used to measure momentum on a scale of zero to 100. A stock is considered to be oversold if the RSI reading falls below 30.In the case of Transportadora de Gas del Sur S.A. , the RSI reading has hit 29.9 — by comparison, the universe of energy stocks covered by Energy Stock Channel currently has an average RSI of 39.0, the RSI of WTI Crude Oil is at 41.9, the RSI of Henry Hub Natural Gas is presently 44.8, and the 3-2-1 Crack Spread RSI is 63.8. A bullish investor could look at TGS's 29.9 reading as a sign that the recent heavy selling is in the process of exhausting itself, and begin to look for entry point opportunities on the buy side. Looking at a chart of one year performance (below), TGS's low point in its 52 week range is $11.575 per share, with $24.22 as the 52 week high point — that compares with a last trade of $19.56. Transportadora de Gas del Sur S.A. shares are currently trading down about 2.5% on the day. According to the ETF Finder at ETF Channel, TGS makes up 3.17% of the iShares MSCI Argentina and Global Exposure ETF ( AGT) which is trading lower by about 2.1% on the day Friday.