FAP, May 27 (Xinhua)-- the risk of default on US debt is approaching, triggering an upsurge of risk aversion among Wall Street institutions. Banks and asset regulators on Wall Street are gearing up for a possible default by the federal government, Reuters reported Monday. A debt default could lead to a sharp rise in US bond yields, a plunge in the stock market, a freeze in the short-term funding market and other vicious consequences. Some Wall Street financial institutions that rely on Treasuries are shunning government bonds that mature in June, while others are preparing to deal with government bonds that are at risk of default.