A look at the weighted underlying holdings of the SPDR— S&P— Transportation ETF (XTN) shows an impressive 10.2% of holdings on a weighted basis have experienced insider buying within the past six months. Start slideshow:10 ETFs With Stocks That Insiders Are Buying » Avis Budget Group Inc (CAR), which makes up 2.59% of the SPDR— S&P— Transportation ETF (XTN), has seen 2 directors and officers purchase shares in the past six months, according to the recent Form 4 data.