A study of analyst recommendations at the major brokerages shows that Calpine Corp ( CPN) is the #44 broker analyst pick among those stocks screened by The Online Investor for strong stock buyback activity. To make that list, a stock must have repurchased at least 5% of its outstanding shares over the trailing twelve month period. In forming the rank, the analyst opinions from the major brokerage houses were tallied, and averaged; then, the list of stocks with strong buyback activity was ranked according to those averages.Investors are often keenly interested in knowing which companies are buying back their own stock, because companies often will only make such a move if they feel their stock is undervalued. Calpine Corp is a company with strong buyback activity that is also considered a compelling buy by analysts; a bullish investor could take this to mean that sharp analyst minds came to the same bullish conclusion as the company itself that the stock is a good value, and therefore the stock should do well in the future. Analysts studying companies buying back their own stock will also factor into their analysis that future earnings will now be spread over a smaller share count, thereby increasing the per-share earnings the remaining shares will enjoy, versus what that same number would have been absent the stock buyback activity. According to the ETF Finder at ETF Channel, CPN makes up 2.08% of the WilderHill Clean Energy Portfolio ETF (PBW) which is trading higher by about 0.4% on the day Friday. CPN operates in the Electric Utilities sector, among companies like Companhia Paranaense De Energia - COPEL (ELP) which is down about 2.5% today, and Companhia Energetica de Minas Gerais - CEMIG (CIG) trading lower by about 0.4%. Below is a three month price history chart comparing the stock performance of CPN, versus ELP and CIG.