This report examines the importance to the U.S. economy of China's investment in U.S. securities, as well as U.S. concerns over the possibility that China might unload a large share of those holdings, including the likelihood that this would occur, and the potential implications such action could have for the U.S. economy. The report concludes that a large sell-off of Chinese Treasury securities holdings could negatively affect the U.S. economy, at least in the short-run. As a result, such a move could diminish U.S. demand for Chinese products and thus could lower China's economic growth as well.