The CBOE Volatility Index, or “VIX,” related exchange traded funds surged Thursday as the equities market declined the most in eight weeks, weakening on the sell-off in Apple (NasdaqGS: AAPL) and another turn in the Russia drama.

The iPath S&P 500 VIX Short Term Futures ETN (NYSEArca: VXX), a VIX-related exchange traded note, increased 6.8% Thursday while the ProShares VIX Short-Term Futures ETF (NYSEArca: VIXY) rose 6.6%.

Additionally, for the more aggressive traders, the leveraged ProShares Ultra VIX Short-Term Futures (NYSEArca: UVXY), which tries to reflect two times or 200% the daily performance of the S&P VIX Short-Term Futures Index, jumped 13.8%.

The Volatility Index was hovering around 16.0 at last check Thursday. The VIX typically moves higher when stocks plunge. Investors would turn to S&P 500 options to protect their portfolios against any sudden dips. Despite the recent gains in the VIX, the index is still drifting around its historical average.

The VIX jumped on fears of a market correction after the S&P 500 experienced its largest drop since April as Apple shares weakened on problems relating to its new smartphone and concern that Russia could seize foreign assets, Bloomberg reports.

“We could have a pull back of 5 percent anytime if you have a confluence of factors that impact investor psychology or geopolitical factors that seem to get out of control,” Marshall Front, chief investment officer at Front Barnett Associates LLC, said in the article. “Stocks are no longer undervalued. There are rumors the Russian parliament authorized confiscation of foreign investments, Apple is weighing on the tech sector, and the durable goods top line number was very weak.”

Additionally, price declines in assets like commodities, emerging market investments, high-yield bonds and small-cap stocks reveal a diminishing appetite for risk and lower expectations for global growth.

“The poor performance… is a harbinger of lower liquidity, the end of excess returns and the end of excessively low volatility,” Michael Hartnett, Merrill’s chief investment strategist, said in a note, the Wall Street Journal reports.