Most traders will recall the early August stock market swoon when fears about waning U.S. economic growth sparked a bout of intense volatility. Adding to the ructions was a sharp appreciation in the Japanese yen following a Bank of Japan interest rate hike.

The yen hit a two-month high in the upper 151 range against the U.S. dollar Thursday in Tokyo, as speculation grows that the Bank of Japan could further raise interest rates sooner than expected. The yen's appreciation came after BOJ policy board member Naoki Tamura said the bank should hike its policy rate to at least 1 percent by the latter half