A study of analyst recommendations at the major brokerages shows that TopBuild Corp (BLD) is the #2 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. TopBuild 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, BLD makes up 3.04% of the PowerShares Dynamic Building & Construction Portfolio ETF (PKB) which is trading lower by about 2.7% on the day Thursday. BLD operates in the General Contractors & Builders sector, among companies like Horton Inc (DHI) which is off about 2.4% today, and Lennar Corp (LEN) trading lower by about 1.8%. Below is a three month price history chart comparing the stock performance of BLD, versus DHI and LEN. BLD is currently trading off about 3.6% midday Thursday.