Which 1973 event intensified the global bear market by causing a major oil-price shock?

The 1973 oil crisis intensified the global bear market by causing a major oil-price shock.

The crisis began after Arab members of OPEC and several other oil-producing countries imposed an embargo on countries seen as supporting Israel during the Yom Kippur War. Oil production was cut and prices rose sharply, creating inflationary pressure and damaging economic growth in many oil-importing nations.

The shock coincided with already difficult financial conditions. The Bretton Woods monetary system had broken down, inflation was rising, and stock markets had been weakening. In the United States, the broad bear market of 1973–74 eventually produced a decline of almost half in the S&P 500 from its 1973 high to its 1974 low.

The 1973 crisis is sometimes confused with the separate 1979 oil crisis, which followed the Iranian Revolution. Both produced energy and inflation concerns, but they were distinct events. The 1973 embargo ended in March 1974, although oil-market effects continued.