Watch Art Cashin: This is 'nagging' at the market
Art Cashin says concerns about a possible shutdown of the U.S. government and a potential political stalemate in Germany are "nagging" at the stock market,
Cashin, UBS' director of floor operations at the NYSE, told CNBC's Bob Pisani around midday they are two "doubts" that have not yet become "great concerns" but are putting a drag on stocks.
"The market is not in a panic. There's reasonably light volume."