NEW YORK, March 12 (Reuters) - The Cboe Volatility Index , known as Wall Street’s “fear gauge,” jumped on Thursday in its biggest-ever one-day surge as U.S. stocks confirmed a bear market and the benchmark S&P 500 index tumbled 9.5%.

The VIX ended Thursday’s session at 75.47, a more than 21-point jump over its already elevated closing level of 53.9 on Wednesday. The index is at its highest level since November 2008. (Reporting by April Joyner; Editing by Sandra Maler)